Beneath the Surface
by Racingwolf
Summary: When a new large - and extremely powerful - group of enemies appears seemingly out of nowhere and attacks Canterlot, Twilight and her friends have to sneak into their underground lair to find and stop the source of their power. Then things get complicated.
1. Prologue

**Beneath the Surface**

**Prologue**

A small unicorn filly, flanked by two guards, headed deeper into a dark cavern, thinking about the daunting task that lie ahead of her. On both sides, the cave's walls curved upwards, meeting at the top far above the filly's head and creating a tunnel that seemed to go on forever. She shuddered. Aside from the glow coming from the horns of the two guards beside her, it was completely dark.

"Be careful where you step," one of the guards warned her. It was the first time he'd spoken since their journey had begun.

The filly nodded, not looking at him. She made sure to keep her eyes focused on the cave walls. She didn't like staring into the yawning emptiness that loomed straight ahead. She kept her attention on the crystals embedded into the walls, some of them bigger than she was. She even allowed herself to smile a bit as she walked past one, looking at her own red coat and yellow mane reflected back at her. She had to admit, there was a bit of beauty to this place, and it made her feel less afraid. However, she couldn't shake the _wrongness_ that seemed to overshadow everything in the tunnel, darkening even the thought of the beautiful crystals.

She turned her attention to the guard on the left. "So...are you really sure that I have to be the one to do this?" she asked. "Is there really something special about me?"

"Of course," the guard replied gently, ducking his head as he passed under a jutting rock ledge. "You've shown more potential for magic than any foal in the kingdom. We all believe you can do it."

The filly turned her attention to the rocky ground she walked upon. "And...you believe this will help us?"

"It will," the other guard replied. "Trust us, it will."

"Only if I succeed, though...right?"

"And succeed you will. Just remember what you were taught."

The filly said nothing in reply as they continued to walk. She wished someone else, at least one of her friends, could be going with her. But no, they had said her friends were not strong enough. She was the only one allowed to attempt this journey.

"Wait," muttered one of the guards beside her.

She paused, frightened, as the guards both stared into the blackness ahead. She wasn't sure if some monster was about to leap out at her, or if some unseen force of magic was going to descend upon them. She wanted to run back, but she forced her hooves to stay still. She glanced from one guard to the other, wondering what it was they had sensed.

"It's nothing," the other guard said nervously. "Let's keep going."

They carried on, and the filly noticed that the guards were hurrying their pace. She had to strain a bit to keep up with them; they had walked such a long way already and she was exhausted. Something about the look in their eyes frightened her, like they had realized something she hadn't. However, she didn't ask any more questions. Instead, she thought over and over about the ponies back home, the ones who were depending on her and her alone to save them. She could not disappoint them. So, she kept going.

She was almost running to keep up with the guards now, not wanting to ask them to slow down in case there was a good reason for their haste. She couldn't tell what had gotten them to act in such a way; the tunnel still looked the same to her, but she didn't want to ask. If there was something she needed to know, she reasoned, they would tell her.

After what seemed like ages, they came to a halt. In front of them was a wall, blocking further passage through the tunnel save for a relatively small space at its base. The filly tensed; the _wrongness_ she had felt earlier throughout the journey was intensified here. She glanced up at the guards.

"This is where you go on alone," one told her.

"I…" she tried to force the fear out of her voice. "The opening looks big enough. One of you could come with me."

"You know as well as anyone else that there is powerful magic down there," the guard responded. "Magic that even we are not equipped to handle. But for you, the most gifted unicorn we know, it will be different."

Something about the guard's words unsettled the filly, or perhaps it was simply the way he'd said them. She couldn't, however, pinpoint what he'd said that actually seemed amiss. She had been chosen. She had been trained. That was very true. But something seemed…off.

"Okay…" she replied, pushing the feeling away. There was still a part of her that wanted to protest, wanted to shout, _'But I'm not an alicorn!' _or _'Can't you send somepony else?'_ Yet she knew better. If she had been chosen, it was for a reason, and she had to put trust in that. Thinking of what was happening back home, she felt a little less scared and a little more determined. She was going to make things better for everyone. She took a deep breath. "I'm ready," she said, illuminating the tip of her own horn as she turned to the dark opening.

As she walked into the small passage, she pretended she didn't hear the fading hoofbeats of the hastily retreating guards. She pretended that the inky blackness didn't unnerve her. She pretended she couldn't hear the alarm bells ringing in her head as she descended deeper into the earth. When she emerged on the other side of the rock wall, she gazed in both awe and terror at what surrounded her. Then, forcing down her fear, she kept going.

When she returned to her home days later, she brought back what the ponies of her village had so longingly desired. But with it, she also brought something terrible.

* * *

_Author's Note: This is an Alternate Universe; everything is the same except the changelings didn't metamorphosize (there are no "changedlings") and Thorax did not become their leader. Instead, he stayed in the Crystal Empire. This story takes place after season 6._


	2. A Visit to the Empire

**Beneath the Surface**

**Chapter 1 - A Visit to the Empire**

Twilight Sparkle, brimming with excitement, eagerly watched the Crystal Empire come into view through the window as the Friendship Express pulled into the station. Immediately she could tell that it was quite a bit more crowded than usual, not unlike the train she and her friends were currently riding on. It was all to be expected, however, for the first day of the annual Crystal Faire was currently taking place. Twilight, however, was more excited to see Cadance and Shining Armor, and of course Flurry Heart.

There was a hiss of steam and the train came to a halt. The doors to the car were opened, and Twilight and the others waited patiently as ponies began to exit the crowded space.

"I'm sure this year's festival is going to be divine," Rarity commented.

"Yeah, for sure!" Spike replied.

"I know," Fluttershy said. "I heard they will have more animals in their petting zoo this year."

"Yeah," Rainbow Dash agreed, "and we'll have a lot more fun now that we don't have to organize it or worry about setting up any events. We can just enjoy the festivities."

"Speak for yourself," Applejack told her. "I just had to bring some of my favorite apple family recipes this time 'round. The crystal ponies will be amazed when they try this."

"That's nothing," Rainbow Dash replied excitedly. "This year, Cadance is having a finale with crystal magic every night and we get front row seats! They might even ask me to do a sonic rainboom."

"And _what _was that about being glad we don't have to help with the events?" Applejack replied.

Before Rainbow could reply, Pinkie Pie bounced up in her seat, startling them both. "I can't wait! After all the trouble that's happened in Equestria, everypony could use a party."

Twilight turned to Starlight, who was seated next to her. "I'm glad we're all here together. And you'll get to see Sunburst again."

"It's been a while, so it'll be good to catch up," Starlight said. "Plus I've never seen this festival before. I'm…sure it'll be fun."

"Aren't you excited, Spike?" Twilight asked, peering over at the dragon, who was sitting on the seat across from her.

"Of course," he replied. "I've been looking forward to it since Cadance and Shining Armor invited us. And, it'll be good to see Thorax again. We haven't seen each other since that whole incident with Chrysalis."

"Well, with yet another threat gone, all the more reason for a celebration, right?" Rainbow Dash called over to him.

Spike, however, wasn't listening, because he'd noticed that it was their turn to disembark. "Come on, everypony!" he called. Spike and Twilight stepped off of the train first, followed by the rest of their friends. Pinkie Pie appeared last, dragging a large stack of luggage through the train doors.

Rainbow Dash gave her an odd look from where she was hovering overhead. "Uh, may I ask _again_ why you brought this much junk to the Crystal Empire? This isn't exactly going to be a long trip." She glanced to one of the train porters who was dragging even more suitcases toward Pinkie from another section of the train. "Sheesh, even Rarity didn't bring so much."

"I heard that!" Rarity called from up ahead.

Pinkie paused in her attempt to move the luggage off the train. "Well, you see, Rainbow, this year's Crystal Faire is supposed to be even bigger and more amazing than ever! I _had_ to help make sure that happened. So, I couldn't just leave my cotton candy machine back in Ponyville. Or my party cannons, or my candy stash and festive hats and-"

Before she could finish, Spike interrupted. "I know Applejack was bringing some of her own food, but don't you think the crystal ponies would already have stuff like cotton candy, considering they've been setting up for the faire?"

Pinkie rolled her eyes. "Well, _duh._ But a faire can never have enough cotton candy, can it?" She grinned at Spike widely.

"I, uh…guess not?"

Twilight looked around at the ponies crowding the station. Suddenly she spotted a face in the crowd she immediately recognized – her brother, Shining Armor – and ran over to him.

"Twily, you made it!" he cried, wrapping a leg around her shoulders in a warm brotherly embrace. "A little late, but you got here."

"I almost didn't see you there," Twilight responded. "There are sure are a lot of ponies coming to visit." She glanced back at the crowd, no longer able to see her friends because of all the ponies moving about.

"It's all right," Shining Armor replied. "You and your friends can come back to the castle with me. Or you could go straight to the faire. Whatever you want."

Twilight nodded and glanced back to the others. Most of them were making their way over to her, although Spike had been caught up talking to some of the crystal ponies, which was to be expected considering his celebrity status in the empire.

"Actually, before I join in the celebrations, I'd love to go back to the castle and see Flurry Heart," Twilight said.

"Oh, sure thing," Shining Armor replied. "I'm sure she'll be excited to see you."

"Well, if it's all the same to you," Rainbow Dash began, suddenly appearing over their heads, "I'd like to take a look at the festival."

"Oh, me too!" Pinkie Pie cried, having finally gotten her luggage free. She pushed it over toward the others. "But I_ might_ need some help getting all this stuff there."

Applejack sighed and glanced at her small compact cart containing all her apple baked goods. "I'll help ya out. After all, I brought along my own special treats for the faire too."

Rarity levitated a few of Pinkie's suitcases with her magic. "We're right here with you, darling. We'll help you make it a Crystal Faire to remember. You go and see your niece, Twilight."

Spike wandered through the crowd and back over to the group. He glanced around at his friends, most of which were in the process of helping Pinkie Pie, and he noticed Fluttershy struggling with a particularly heavy suitcase. "I'll go with them," he said. "They look like they can use my help."

"All right, you all go look around. We'll meet up with you later," Shining Armor said.

"I'll come with you to the castle," Starlight told Twilight. "I sure hope Sunburst is happy to see me."

"Well, let's get going," Shining Armor said, leading the way.

They happily followed Shining Armor as he led them through the streets toward the castle. Crystal ponies were racing back and forth, moving between the festival booths and talking excitedly among one another as they bustled about. Twilight was happy to see them so joyful. With Cadance and Shining Armor looking over the empire, they realized that things had overall been much better for the crystal ponies and they all hoped for good things to come.

Before long, they arrived at the castle and walked inside. The guards happily let them through, and they walked to the throne room, where Cadance, along with Sunburst and Flurry Heart were waiting for them.

Twilight ran up to Cadance and Flurry Heart with a big smile on her face. "It's so good to see you! Looks like my favorite niece is just as cute as ever." She ruffled Flurry Heart's mane. "Thanks for inviting us, Cadance."

"You're always welcome here, Twilight," Cadance said.

**-ooo-**

Meanwhile, Spike had met up with Thorax outside the castle after helping Pinkie Pie with all her party supplies. Thorax, who had been nervous about going by himself, had decided to wait for Spike. They left the castle and as they entered the street, Thorax's teal eyes went wide as he took in the sights of the Crystal Faire. Ponies were enjoying various activities and games, laughing and talking with one another. He still wasn't used to seeing any group of creatures so happy and carefree.

"Wow," Thorax said. "The Crystal Empire does this every year?"

"Yep. Trust me, you're going to love the Crystal Faire," Spike told him as he gestured toward the many booths and tents lining the streets of the empire. "It's great! They've got games, crafts, jousting… okay, maybe jousting isn't your thing, but you'll probably like the crafts and games, and they do have a petting zoo!"

"Oh, that sounds great! And it's really great to see you, Spike," said Thorax.

"It's nice to be back in the Crystal Empire and be able to spend more time with you, since you are my newest friend," Spike replied, again noting the new sparkly shine on Thorax's wings. He briefly turned his attention to the crystal heart beneath the castle. "You know, the whole point of this celebration is to help uplift the crystal ponies so they can power the crystal heart with light and love. After all Equestria has gone through, that will definitely be a good thing."

Spike had learned that ever since making friends and sharing love in the Crystal Empire, Thorax could now have even more love than he needed. They had quickly discovered that freely given love was much stronger and sustained changelings for longer than stolen love, so he never had to go hungry.

"How are things with you here?"

"Oh, it's great for the most part," Thorax replied. "Some of the ponies are still nervous around me, though. Maybe it's the way I look, or what Chrysalis and the other changelings once did, but it still doesn't feel right to use a disguise."

"Ah, they'll come around," Spike reassured him. "After all, you did help save Equestria."

"I hope they will," Thorax said, glancing down at the holes in one of his forelegs as a few crystal ponies passed.

Spike noticed the sudden difference in Thorax's mood. "You know, even though they didn't have to, it seems like my friends brought a lot of stuff to help out with the celebration. Applejack brought a bunch of her homemade apple specialties. She has pies, jams, tarts, muffins, and fritters. You've got to try some! I bet they don't have anything like it in the Crystal Empire."

Thorax smiled at him as he and Spike began walking toward one of the booths. "Oh yeah, I didn't get much time to meet your other friends after what happened with Chrysalis."

"Yeah, that's right…" Spike replied, lost in thought for a moment. "You know, now that Chrysalis has been overthrown, the changelings are deciding on their new leaders. So they're free to take what you and Starlight showed them and survive off love given to each other. This means that…if you wanted to, you could go back."

Thorax stopped walking. "Yeah, I guess you're right…"

"Well, what I mean is that now you get to decide where you want to live. But you don't have to go back. You can stay here."

Thorax looked relieved, but before he could respond, a shout interrupted them and they both looked up to see Rainbow Dash flying overhead. "Spike, there you are! You've gotta watch me in the jousting tournament. It's just about to start."

"Oh, sure," Spike replied, before turning to Thorax. "You wanna come?"

Thorax nodded, and the two of them raced off after Dash as she flew toward the jousting arena.

**-ooo-**

Sunburst and Starlight left the castle to join the crowds in the street. "It's great to be able to spend some time with you," Sunburst said.

"Haha, yeah," Starlight laughed nervously. "So, anyway, how do you like your job here? Now that you're Flurry Heart's crystaller and magic advisor "

"Oh, it's great," Sunburst said. "And you know, there wouldn't be a royal family, or even an empire to serve had you not stopped Chrysalis."

"Well, it was a team effort," Starlight replied. "I'm just glad I could help after, well…the things I did."

"That is true, but what you and the others did was amazing!" Sunburst said. "If there's anyone who still doubted you, they won't now."

"Yeah, I guess so," Starlight said awkwardly.

"Well, let's not worry about any of that now," Sunburst said. "We're here to enjoy the faire."

"You're right," said Starlight. "Want to go check out the petting zoo."

"Sure," Sunburst replied, and they headed off through the crowd together.

**-ooo-**

When night had fallen, the residents of the Crystal Empire had gathered together in the streets in the center of the empire. Ponies of all ages looked up at the crystal castle, glimmering under the moonlight. Most of the food stands and games had closed for the night, but the ponies had gathered to watch their leader perform her crystal magic.

Twilight had rounded up her Ponyville friends, along with Sunburst and Thorax, to watch the final event of the first night's celebration. Shining Armor had made sure they all had front row seats, but for whatever reason, Pinkie Pie had insisted on sitting in the row behind them.

"Welcome, everypony, to the Crystal Faire," Cadance announced. "I hope you enjoyed the first day and continue to enjoy what's to come. Thank you for making it a wonderful event to celebrate our kingdom's freedom and strengthen our empire. I am proud to have you all as my subjects."

Several of the watching ponies turned their attention to the crystal heart, positioned beneath the castle and held between two sharp crystals by magic. A feeling of pride washed over the ponies, knowing they all played a part in protecting the empire.

Cadance lit her horn, shooting a beam of light into the sky which created a vast aurora over the castle. It shimmered with an array of colors, lighting the night sky and reflecting off the crystal buildings. Both the crystal ponies and those visiting the empire looked at it with awe. Thorax's eyes widened and his mouth dropped open in amazement. He had clearly never seen anything like it.

"I still say it would have looked better with a sonic rainboom," Rainbow Dash whisper to Applejack.

"The Crystal Empire's celebrations aren't bad, huh?" Sunburst asked Starlight.

Starlight smiled back at him. Before she could reply, however, there was a loud bang behind them. Thorax and Fluttershy jumped with cries of alarm and a few of the others nearly fell out of their seats. What looked like pounds of confetti rained down on them, and they turned around to see Pinkie Pie grinning mischievously next to a large party cannon.

"Surprise!" she shouted. "Best Crystal Faire EVER!"

**-ooo-**

After the celebrations had concluded for the night, an exhausted Twilight finally made her way through the castle's glittering crystal hallways and to the room she was to be staying in during her trip to the Crystal Empire. Once she reached the right door, she opened it quietly, noticing that Spike had gotten there earlier than she had and was already curled up asleep in his bed.

She was looking forward to a nice rest; the day had been fun yet tiring, and she wanted to have a good night's sleep before another long, exciting day with her friends and family members. Careful not to wake Spike, Twilight climbed into her bed and curled up with the blankets. Within minutes, she was asleep.

Some time after she drifted off, she found herself wandering the streets of Canterlot. After a bit of time she realized that something was off; several of the buildings in this version of Canterlot sported crystal like the buildings in the Crystal Empire. And suddenly, while she had simply accepted it before, this detail clued her in to the fact that she was dreaming.

She stood still, letting the dream's cool night breeze wash over her, ruffling her mane and feathers. As she looked around, a shape flickered across the moon, then formed into the shape of a pony. Princess Luna appeared, gliding to the ground, and Twilight felt a twinge of anxiety as she realized that Luna looked distressed and worried.

"Twilight, I'm sorry for the intrusion, but Canterlot has been attacked."

"What?" Twilight gasped. Though she was dreaming, she knew very well that Luna, and her message, were real.

"My sister needs my help to protect Canterlot, so I don't have much time," Luna responded. "Earlier this night, a group strange unicorn ponies came to Canterlot." At once, the vision of the crystallized Canterlot around Twilight faded, to be replaced with an image of strange…unicorns? They had the shape of unicorns, but their bodies were pale, almost white, and they had dark blotches on their backs. Stranger still, they had black horns that looked as if they were melting. Every one of them lacked a cutie mark, and their eyes were red with white slit pupils. As she watched the strange ponies gallop past, Luna continued. "Their magic combined was more than even I or my sister could overcome. However, we've managed hold them back and shield Canterlot from their attack. Our powers will be able to keep them at bay for a while, but not forever."

Twilight noticed as the images of the strange unicorns raced by that each of them was wearing a necklace bearing a strange gemstone shaped roughly like a teardrop. She hadn't seen an amulet quite like the ones these strange new ponies wore, and she wondered briefly if_ that_ was the source of their power.

"They were after my sister," Luna said. "At first they tried to come peacefully to ask Celestia for help in reversing a curse that had been placed on them. No one knew of these unicorns, but as they talked with my sister, something triggered a memory and Celestia remembered who they once were. She then also remembered what they had wanted of her."

"This happened while I was imprisoned," Luna continued, "but my sister told me that they were once a town of ordinary unicorns that mined gems with magical properties. She told me that she later learned that something happened to threaten them, and they tried to take matters into their own hooves. They uncovered a dangerous artifact, and within weeks, the ponies who lived in the town started to become afflicted by a curse. This happened over twenty years ago, and the last thing they did before they vanished, both from the surface and the memory of everypony who once knew of them, was to ask Celestia to find a second artifact and use it to reverse their curse."

Twilight watched Luna in silence.

"When they came to Canterlot today, they asked for Celestia's help again. But with her newfound memory of them, she remembered that in order to do so, she would need to give up her life force to power an artifact they cannot get close to reverse their curse. When my sister refused their request, they attacked, using artifacts and magic we had never seen."

"Why would they demand something like that? And Celestia doesn't know-"

"We don't know the extent of the power they have on their side, no. But before we put a magical barrier up to Canterlot, one of our guards managed to overhear some things from these intruders. Their leader, Scarlet Rose, is not with them in Canterlot. She is in the plains between the Crystal Empire and Canterlot, in a series of caves connected with the mines these ponies once used in their former home. Celestia is sure that the source of their unique power is there. The same artifact that cursed them." An image of what Celestia had described appeared, an artifact made of crystals forming a diamond shape, with two twisted crystals in the middle.

"Is that what they want Celestia to power?" Twilight asked.

"No, there is a second artifact similar to it, and they believe that retrieving it will reverse the curse, and that only Celestia could do it. Apparently, few of the unicorns themselves can get close to the second one. But this one-" She turned her attention toward the image of the crystal artifact. "-Is what caused the curse in the first place. Celestia said that you'll know when you're close to it, because of its dark magic energy. If you and your friends can find it and destroy it, they will have no more magic than ordinary unicorns. The artifacts they've created may lose some of their power too, and if not, then at least that will be all we'd have to deal with."

Twilight narrowed her eyes in determination. "All right. We'll do whatever we can to help."

"The artifact is in the caves, and will certainly be heavily guarded, so be careful."

"I know, but…I still don't understand just why they want this," Twilight said. "What would Celestia have to do? Why would it destroy her?"

"They firmly believe the only way to reverse the curse is through that second ancient artifact," Luna responded. "However, from what my sister knew about them in the brief time before they vanished, the few unicorns that have been able to go near it have tried to activate it, and lost their lives doing so. They believe Celestia is the only one who could power it, but we are worried that she would meet the same fate. Celestia believes it is too dangerous to risk it, and it may not even work. But these ponies will not take no for an answer. They don't care if Celestia lives or dies and would simply use the magic she poured into the artifact to raise the sun themselves."

Twilight thought to herself. It seemed strange that they would just be arriving at Canterlot now, twenty years after the first attempt. She wondered why they hadn't asked Celestia for help again sooner. There seemed to be a lot missing from the story, and from the look on Luna's face, she didn't have the answers either. However, whatever was going on, she was determined to find out and help her mentor.

The images of the cursed unicorns slowly faded around Twilight, and a hazy image of Canterlot replaced them. "We're counting on you," Luna said. "We'll hold them off at Canterlot as long as we can. I will contact you again soon." Luna and the rest of the scenery around her faded away.

Twilight woke with a start.


	3. Operation Infiltration

**Beneath the Surface**

**Chapter 2 - Operation Infiltration**

"I can't believe anypony would ask something like that of Celestia," Cadance said. "Let alone attack after she refused."

Twilight, Spike, and all six of her friends from Ponyville had gathered in the throne room early that morning. Cadance, Shining Armor, Sunburst and a number of guards had listened as Twilight retold what Luna had revealed to her in the dream.

"And that's…everything that Luna told me," Twilight replied. "She said Celestia was the only one who remembered these ponies. I don't know how we're going to find their artifact when we know so little about them!"

"I just don't understand why this is happening now," Starlight said. "If this happened around twenty years ago, why did they only just now think to try to force Celestia to comply? And if they had so much magic, why did they make it so obvious that they were trying to get to Celestia instead of trying to set a trap or surprise them?"

Spike raised his eyebrow at Starlight.

"I'm just trying to figure out their logic here," she said sheepishly.

"Twilight did say that Celestia recognized who they were," Fluttershy pointed out.

"Maybe they needed stronger magic so they could be sure?" Rainbow Dash suggested from where she hovered near Starlight. "I mean, if this artifact they have is making their magic so strong, maybe it took a while before they were strong enough to pose a threat?"

"I'm not sure that's how the artifact works," Twilight replied, pacing back and forth. "But I guess it could be. Maybe the effect of its power on their magic was a slow process. I'm not sure. But Starlight, I wondered the same thing. Why would they wait until now? Even Luna had no idea."

"Well, I guess that part doesn't matter at the moment," said Applejack. "They're here now and we gotta stop 'em."

"I suppose that is true," Rarity added. She turned to Twilight. "Luna didn't say anything about _where _in these caves we might find their artifact?"

"No," Twilight sighed. "Just that we'd feel its dark magic when we were getting close."

"Well, I wouldn't worry. We've done much more difficult things before," Rainbow said.

"I don't know, these mines and caves seem like they could be huge," Fluttershy said softly. "I'm not sure this is much to go on."

"And that's my problem," Twilight replied, continuing her anxious pacing. "We barely know anything about these ponies, and we're supposed to walk right into their lair and destroy the one thing they have that might allow them to overthrow Celestia. The one thing that would give them enough power to bring back this 'second artifact' so they could force her to…to…"

"Twilight, take a deep breath," Cadance said. "No one's going to let them force Princess Celestia to risk her own life."

"Yeah," Pinkie Pie added cheerfully. "Celestia trusts us to fix this mess, and it's not without good reason. We'll get through this just like we've gotten through everything else."

Twilight smiled at them, but the smile quickly faded. "Well, I was thinking…when we find their artifact, how are we going to destroy it? Luna said that it would be heavily guarded. And also that 'Scarlet Rose,' who is apparently the leader of these strange unicorns, is back in the caves too, maybe guarding it herself."

"I suppose there's not much we can do about that until we find out more for ourselves," Rarity sighed. "If Luna and Celestia don't know much about these ponies or their artifact, I'm not certain anypony else would."

"That's another thing I find weird," Starlight pointed out. "How nopony has heard of these unicorns. If they mined magical gems, surely somepony would have one or remember where it came from."

"I wish we had more time," Twilight said, her ears drooping. "There might be a mention in a book or, or something-"

"Not here in the Crystal Empire," Spike responded. "These ponies disappeared years before the Empire returned."

Twilight sped up her pacing. "Yes, but maybe in Canterlot – if it weren't being attacked – or Manehattan, Las Pegasus, or…argh, there's no time for that." Twilight brought her hoof to her face.

"Look, even if there was, it would have been written before these ponies were cursed, right?" Starlight replied. "So, a book on this might not be much help even if it did exist."

"But what if there were a map of their mines and the caves or something?" Twilight asked. She gritted her teeth in frustration. "Their history can't have just vanished!"

"Well, it's not like it's the first time it's happened," Spike said. "I mean, look where we are." He glanced around the crystal throne room.

"Yes," Twilight replied, "but Luna said that this happened around twenty years ago, not a _thousand_ years!"

"Erm, Twilight," Sunburst said, speaking up for the first time since Twilight had told them about Luna's visit to her dreams. "You told us that Luna showed you what the artifact that these strangers had looked like, and that they wore amulets around their necks. Perhaps if you could show me, I'll see if I recognize them from anywhere?"

Twilight looked at him with sudden relief. "Yeah, I can do that," she replied, feeling a bit calmer. Sunburst's knowledge of magic was greater than anypony else's in the empire. "I'll just need to get some paper and-"

"No need," Shining Armor said, levitating a stack of paper and some pencils that had been sitting beside the throne. "I thought you might be wanting somewhere to write things down after hearing something so important."

"Thanks," Twilight replied, taking a few pieces of paper and a pencil with her own magic and bringing it to the floor in front of her. After several minutes of moving the pencil around with her magic, Twilight was satisfied enough that the drawings depicted what she'd seen and turned them over to Sunburst.

The others in the room gathered around as Sunburst adjusted his glasses and peered closer. Twilight's drawing depicted an artifact made of four crystals fused together, forming a diamond shape, and two more crystals twisting together in the center.

"It might not be completely accurate," Twilight said nervously. "Luna created this image going by Celestia's description, but it looks somewhat like that. Have you ever seen anything like it?"

To her disappointment, Sunburst shook his head. "No," he replied. "I've read up on a lot of artifacts, but I haven't heard of anything like this one."

"Well, it was worth a shot," Rainbow said with a shrug.

"How about the amulets?" Twilight asked as Sunburst shuffled the papers so he could see the drawing of the tear-drop-shaped amulets. "Every one of those strange unicorns in the dream was wearing one."

Sunburst studied the drawing for a few moments. "It…could be made of any number of magical gems," he replied. "Did Luna show you one of these in detail?"

"Not really," Twilight sighed. "They were a clear light blue, though. And they had what looked like white or yellow streaks running through them."

Sunburst's eyes lit up. "I might know what they are," he said, and the others looked to him with excitement. "There's a type of rare gemstone called ice topaz. It has fairly limited magical qualities that can be activated by a talented spellcaster. However, the only thing I've ever heard of these gems being able to do is to make a pony able to withstand extreme environments, like deserts or frozen mountainsides."

"Why would they need that to attack Canterlot?" Rainbow Dash asked.

"Maybe their caves are so cold, the rest of Equestria seems boiling hot in comparison," Pinkie suggested.

"Well in that case, we'd need to bring protective clothing ourselves," Rarity added. She sighed. "Too bad I left my winter wardrobe back in Ponyville."

"I don't think we'll need that," Twilight said, trying to sound confident. "If regular unicorns could mine for gems all those years ago, the caves can't be such a hostile place. And if for some reason that's changed, I know a few spells that will keep us safe at least for the time we'll be there."

There was silence for a few moments as Twilight's friends glanced to one another, each with their own thoughts about the upcoming task.

"Well," one of the pegasus guards present in the throne room said, "we have our full trust in you. With Spike the Brave and Glorious at your side, I am sure you will be able to find and destroy this artifact before Luna raises the moon tonight." Other guards voiced their agreement.

"Y-yeah, of course," Spike replied. He looked to Twilight, who still seemed worried, and started to feel more uncertain himself.

**-ooo-**

After Twilight and her friends had prepared as quickly as they could, it was decided that Twilight and Starlight would teleport the group to the location of the cave. Teleporting multiple ponies at once over a long distance used up a lot of magical energy, so they had chosen to make the trip in several shorter "jumps." Their group was divided into two; Starlight would teleport Rarity, Rainbow Dash, and Fluttershy, while Twilight would take Pinkie Pie, Applejack, and Spike.

The first series of teleports went without a hitch; they moved from the Crystal Empire and south toward Canterlot, Rainbow Dash flying overhead to check their position each time they stopped. During the last teleport, however, something went wrong. Twilight had planned her destination to be further south, but a mere fraction of a second after she and her group vanished from the last point, Twilight felt as if she'd suddenly hit an invisible wall, and then she and the others were suddenly heaped together in an awkward pile quite a ways away from where Twilight had planned to end up. Several trees and bushes surrounded them. Starlight's group was nowhere in sight.

"Uh…what just happened?" Applejack asked as she attempted to untangle herself from everypony else.

"I'm…not sure," Twilight said, rubbing her head. "I guess we just-"

"Twi?" a voice called from above, and the four looked up to see Rainbow Dash flying overhead. "Something, uh…went wrong with Starlight's teleportation spell. We ended up back there a ways." She pointed with her hoof.

"Go bring them here!" Pinkie Pie cried. "Or maybe have Starlight try to teleport again. That was kinda fun."

"Uh, I'll just bring them over," Rainbow replied. "They're not far."

A few minutes later, Starlight and the others with her trudged through the bushes to meet Twilight's group. "I know _exactly _what this is," Starlight growled. "Chrysalis had a throne made up of some sort of magic-absorbing stone. And when Discord tried to teleport us, this same thing happened. Couldn't get close using magic."

Though Twilight had been relieved to see the others, her expression immediately changed to one of worry, and her friends looked more nervous. No one had planned on not being able to use magic.

"Let me see," Twilight said. She walked a few paces forward and lit her horn. Several of the leaves littering the ground around the trees glowed and lifted into the air, but after a few seconds, the glow faded and they floated back to the ground.

Rarity closed her eyes and focused, but nothing about her horn changed. "I can't use my magic at all!"

Starlight narrowed her eyes, and a few tiny sparks came from her horn. She sighed. "Figures," she said. "They're definitely blocking magic _somehow._ Twilight's must work a bit better because she's an alicorn, but it's still not much."

"Well," Applejack said, "if they want Celestia to power that second artifact they can't reach, there's gotta be some way other magic can work down there."

"Yes, but probably not unless they want it to," Fluttershy said nervously.

"Well, let's try to get closer and see what we can find out," Rainbow said.

They carefully walked through the bushes, not sure exactly how far they were from the cave. Luckily, up ahead, the trees began thinning out and soon they could see ahead into a wide field with what looked like a recently opened pit in the center. It was surrounded by eerie-looking unicorns, each of them wearing the amulet that Twilight had described.

Concealed among some bushes, Twilight and the others could see the unicorns from a distance, not close enough to be seen or heard. However, they knew if they left their hiding place, they would be seen immediately; there was no cover in the field. At least a dozen unicorns stood or paced near the cave entrance. All of them sported ghostly pale coats with black markings, though there were subtle differences in color between each one.

One of the unicorns, a stallion, lit his melted-looking horn and used his magic to move a large boulder out of the pit and flung it a good distance away.

"Well, _their_ magic works," Rainbow grumbled.

"Well, whatever they're using to block magic, it can't be the same stuff Chrysalis used, because they aren't changelings," Starlight stated. "It's probably some powered-up spell they're using with the help of that cursed artifact."

Twilight looked worriedly at the odd unicorns, so many of them guarding a cave entrance quite smaller than she'd imagined. "Without any magic, I don't see how we're going to get in undetected. But maybe, if there were another entrance..."

"We could always make one!" Pinkie suggested. "Come on, everypony! Let's get some shovels and start digging!"

"Without magic?" Rainbow retorted. "That would take forever! And how would we do something like that without them noticing?"

"Well, we have to find some way in. Celestia and Luna are counting on us," Twilight said, deep in thought.

"Maybe we could distract them?" Rainbow suggested.

"_All_ of them?" Applejack replied.

"That doesn't sound very likely," Rarity admitted.

"The cave's connected to some mines, right?" Applejack said. "Well, then there must be other entrances. We've just gotta find 'em."

"Wouldn't they guard those too?" Fluttershy asked.

"Not if they were _secret_ entrances," Pinkie said.

"They'd be protected by spells or who knows what else," Fluttershy replied, shaking.

"We've got to try!" Applejack protested.

Rarity looked to the earth pony with worry. "It could take forever to find any hidden entrances!"

"Isn't that better than doing nothing?"

"Hey, uh, let's just think for a moment, okay?" Starlight asked, clearly nervous as she watched the others. "I'm sure we can come up with a plan."

"Luna didn't know anything about magic being blocked, though," Rainbow said.

Spike glanced from one mare to another, each of them sounding increasingly worried as they talked back and forth. He fidgeted with his claws nervously. "Um, guys?" he asked, but the ponies continued with their frantic debate. "Guys?" When still no one turned his way, he blew a small plume of fire into the air, careful not to make it too big or bright so it wouldn't be seen above the foliage. "_Guys?_"

One by one, the ponies turned to him, still looking troubled.

Now that he had their attention, Spike was glad he didn't have to raise his voice and risk somehow being overheard by the unicorns in the distance. "Uh, this could be a shot in the dark, but…maybe we could see if_ changeling _magic works?"

**-ooo-**

"Thorax, we think we might be able to use your help to get into the cave and help us find the artifact powering these unicorns' magic," Twilight said.

She and Spike had teleported back to the Crystal Empire and met with Thorax in the castle. They were currently standing in one of the hallways where they had run into him. Thorax hadn't been surprised by what the two had told him. In fact, it had been clear that he had already been worried about it.

"Cadance and Shining Armor told us what was happening in Canterlot," he explained. "I'm sure word has spread through the whole empire now. How can I help?"

"The ponies that attacked Canterlot have some sort of spell or something blocking magic around their caves, and it's probably being used throughout the whole cave system," Twilight told him.

"But their own magic works, though," Spike added. "So, it can't be preventing every kind of magic, and I thought maybe it wouldn't work on changelings."

"We're not completely sure about this," Twilight continued, "but if you can use your changeling magic, it might make all the difference. If you're able to transform into one of those unicorns and find a path through their cave to another entrance that's less guarded, we could sneak in without attracting attention."

"Of course, I'll try," Thorax said. "After you helped me so much, it's the least I could do."

"Thank you," Twilight replied. "I really appreciate it. We kinda ran into more trouble than we bargained for."

"Well, if it will help protect Canterlot, I'll do whatever I can." Thorax said, giving Twilight a smile.

"I know you can help us, magic or not," Spike said, resting his claws on Thorax's shoulder. "But let's hope these cave ponies haven't thought of changelings."

Twilight smiled back at them. "I already told Cadance and Shining Armor that I was looking for you, so we can teleport whenever you're ready."

"I can leave right now," Thorax said.

"Yeah," Spike added, "what are we waiting for?"

"Then let's go," Twilight said with another smile, her horn taking on its glow.

Now that Twilight had taken the teleportation path to the cave entrance twice, it was mere moments before the three of them were standing in the grove of trees where the others had been waiting. Thorax took a moment to take in his surroundings as the group of mares gathered around and looked to him, Twilight, and Spike expectantly.

Starlight sent a few tiny sparks out of the tip of her horn. "As you can see, Twilight, Rarity, and I are kind of out of luck."

Thorax seemed suddenly nervous as he looked from one pony to another, but he focused his own magic, and in a flash of teal light, an exact copy of Starlight was standing in front of the group.

"It worked!" Pinkie Pie squealed.

Twilight grinned, looking far more hopeful about the situation than she had since she'd first told the others about Luna's visit to her dream. "This changes everything."

"See? Good thing they didn't think of changeling magic, huh?" Spike said.

"All right, let's find a way in and do this!" Rainbow added.

"Thanks a lot, Thorax," Spike said, turning to the changeling. "I don't know what we'd do without you." He was relieved that Thorax hadn't been all the way over at the Changeling Kingdom. It would likely have taken a big toll on Twilight's magical energy if she'd had to teleport all the way there. Though the changelings were peaceful now, and ponies were working with them to learn friendship and share love with each other, Thorax had chosen to go back to the Crystal Empire after Chrysalis was overthrown. One of his reasons for doing so was that he wanted to learn more about friendship so he could better help the other changelings when he was ready. The changeling hive had been a bad experience for him from the beginning and he was not ready to even visit for long. Most importantly, he had wanted to stay among his first ever friends.

Thorax changed back to his normal form as Twilight led him over to the group of bushes at the edge of the clearing, from where they could view the cave entrance – and their enemies – from a distance. Several of the unicorns were levitating rocks away from the hole in the ground, likely trying to widen it. Their magic tossed even boulders a great distance with little effort. One of them was even using magic to crush the boulders into pieces.

Thorax's eyes widened and he backed further into the bushes. "So I…just go in there, and try to find another entrance?"

"Yes, that's it," Starlight said.

Twilight noticed that Thorax was shaking. "Look," she said, "I want to make sure you're okay with going through with this. It would help, but if you don't want to, we can find another way."

"No, no! I can do it," Thorax quickly corrected. "After everything everypony has done for me, I really do want to help."

Starlight, remembering the panic Thorax had had in the changeling hive, said, "Look, you've got this. We've faced worse than this before." She tried to look confident in spite of the worry she felt deep down, and gave the others a smile.

"Exactly," Spike added.

Thorax walked back up to where he could peer through the bush again, several of the others gathering on either side of him. They watched as about half of the odd unicorns continued to levitate rocks away from the cave opening, while others sat watching like guards.

"All right, these ponies probably all know and recognize each other," began Twilight, "so I guess we just wait for some of them to go back inside and Thorax will take the place of one of them and act like he teleported outside to-"

"Well, there goes one right now," Spike pointed out.

Sure enough, one of the stallions, his sickly pale coat tinted blue, threw a boulder aside with his magic and stomped back toward the cave opening. A mare saw him and called out.

"Hey, where are you going?"

The stallion narrowed his red eyes. "Comet said that he wanted help with the amulets. They've got Jade and the others working on them, but they could always-"

"Fine, fine," the mare said with a shrug. "Better you than me."

The stallion marched toward the cave opening and disappeared into the gloom. Most of the other pale unicorns paid him no attention.

"Perfect," Rainbow Dash muttered with a grin before turning to Thorax. "Think you can copy his voice, in case they ask you anything?"

"Oh, uh, sure," Thorax replied. "I can copy any voice."

They waited for a while, until they were relatively sure that nopony would question why the stallion was suddenly outside again. Thorax couldn't do a teleportation spell himself, but if these ponies could show up at Canterlot so unexpectedly, they were likely capable of it and would assume the stallion that Thorax was impersonating was too.

When they were sure they were ready, Thorax transformed himself into an exact replica of the stallion, complete with a false image of a teardrop-shaped amulet.

"Oh, perfect," Rarity said. "Now, go out there and do your thing."

Thorax crept around the bushes until he was sure he was far enough away from the rest of his group, then he emerged into the field surrounding the cave entrance. He walked toward the group of pale unicorns, trying to act calm and sure of himself, but he was sure he looked nervous. The other unicorns, however, didn't pay him any attention until he reached the mare that had talked to the bluish stallion earlier.

"I thought you were going to meet Comet," she said, unimpressed.

Thorax had no clue who Comet was, but he tried not to show any uncertainty. "Oh…yes, I-I came out here to check something. I'm going back there now."

The other unicorn looked at him strangely, and for a moment he thought that she would uncover his secret and realize that he was an imposter, but she merely gave him a bored look and turned away from him. "Whatever. Just don't slack off."

Feeling relieved, Thorax walked forward. He was not interrupted again as he made his way to the cave entrance, ducking to avoid a rock levitated by another unicorn, and crept down into the tunnel.

The first thing he noticed was that the cave did not feel cold; in fact, it was uncomfortably hot. As he pressed further into the darkness, lights appeared ahead, standing out like beacons in the gloom down below. As he approached, he noticed that they were round, pearly white crystals that glowed with their own light. They were spaced evenly throughout the tunnel as far as he could see.

When he walked in front of the closest one, he was startled as an image of himself – or rather, of his pale unicorn form – flashed across its surface briefly. He noticed flashes on the other orbs of light that shone from the darkness ahead, but they were so brief that he almost wasn't sure he hadn't imagined them.

He stopped walking and froze. He waited, but nothing else happened, and the glowing orb on the wall above him remained as white and murky as it had first appeared, giving off its dim glow. Keeping his eye on it, he slowly crept forward, unsure of what was going to happen. He didn't notice the other unicorn emerging from a side tunnel until he walked right into him.

The unicorn, another stallion, gave a cry of surprise and backed up, shaking his inky black mane.

"S-sorry!" Thorax stammered, backing up toward the crystal again.

To his surprise, the unicorn gave him a smile. "No problem," he replied, walking past Thorax and toward the surface. As he did so, Thorax noticed the other unicorn's image flash in the crystal orbs. The cave unicorn gave no reaction.

Thorax felt a bit safer as he continued on, noticing more side tunnels the deeper he got. Some of them were lit with crystal orbs, like the main tunnel was, but others were dark, some of their entrances half-blocked with rock. After several more minutes, he emerged into a fairly large cavern with tunnels branching in several directions. There were even some higher in the wall, and steps had been carved into the stone to allow unicorns access to those tunnels.

He could hear voices coming from a few of them, and he moved toward the wall, suddenly afraid of what would happen if he ran into the unicorn he was impersonating. He looked at each of the tunnels, none of them indicating where they led to. He noticed that one had more light shining from it than the others, and he crept closer.

It was immediately clear why; the bright tunnel was much shorter than the others, and from what he could see, it led to a massive cavern. He could see the tops of tall stone buildings, each one shining with light far brighter than anything else in the cave he'd seen so far.

He heard hoofbeats, and the head and shoulders of a unicorn came into view at the other end as she climbed some steps up into the tunnel from the big cavern's side. Thorax pulled his head back and looked around. There was no point in exploring the brightly lit tunnels; if there was an exit at the end of them, it would be guarded. He moved toward one of the dark tunnels, noticing once again that the crystal balls on the walls picked up his image and sent it along a line of them in sequence. Sending the image off to somewhere, or _somepony_ else.

Thorax ducked into the dark tunnel as the mare emerged from the tunnel, not even glancing his way before heading off down one of the other brightly lit passages. He breathed a sigh of relief and began making his way through the blackness.

Once he'd turned a corner and was sure any light he created wouldn't be seen by anypony in the other cavern, he lit his horn, which still shone the color of his changeling magic. He noticed immediately that it looked like the tunnel was abandoned; hoofprints stopped appearing when he went further in. He soon realized why.

Up ahead, the tunnel was blocked in a cave-in that must have happened a while ago; the rocks were coated in dust. Dejected, he backtracked until he was back in the larger cavern, and chose another tunnel.

For what seemed like ages, he searched dark passages, trying to stay out of sight of the crystal orbs in case his behavior would be seen as suspicious. He was quickly realizing that the place was one gigantic maze, though at least, unlike the changeling hive, the tunnels remained consistent. To avoid getting lost, he kept track of details in each tunnel, and didn't venture into the many side-tunnels unless he felt cooler air coming from them.

He saw several strange things in his wanderings. He came across carvings in the cave walls, broken crystal orbs, and strange spider-like creatures that skittered into the darkness when his light came near. Strangest of all were the times he came across underground plants, growing completely without sunlight and bearing strange fruit on their branches. Having never seen or heard of anything like them, he kept his distance.

He came across tunnels flooded with water or mud, mineshafts that dropped into impenetrable darkness, and a few more cave-ins. He was growing increasingly worried, even though he'd scattered small stones in places to show himself where he'd been, when he finally had a stroke of luck.

One of the unused tunnels he wandered through suddenly blasted him with cool air, and he noticed a side tunnel that was leading upward. He placed some pebbles in front of it before climbing in, feeling more cool air brush against his short unicorn coat. The tunnel was much narrower than most of the others, enough to make his anxiety intensify, but he pressed onward, following the scent of fresh air.

And then he saw light that wasn't coming from his horn. Up ahead, what remained of a thick wooden door blocked an exit, and light shone through from gaps in the worn-down structure. _Sunlight._

Thorax went up to push the door open, and a feeling like a shock went up his leg, making him stumble back. He could see a faint shimmer over the door. An old spell. He backed up, realizing that whatever protection spell was on the door had to have weakened over time. The glow in his horn intensified as he prepared to fire a beam of energy. He'd never really practiced this except when forced; he was no fighter, but when he fired the magic at the door, half of it broke off and crumpled to the ground, the last remnants of the spell on it vanishing.

Thorax crept out of the tunnel, relieved to be out in open air again. From what he could tell, he hadn't been in the cave longer than a few hours. Looking around, he saw trees and thick underbrush, and there weren't any signs of a pony being there recently. Happy and relieved that he'd found what his friends were looking for, he headed into the tunnel to follow his path back to the main cave entrance and find the others.

**-ooo-**

Without incident, Thorax made it back to the area he remembered, the brightly lit cavern with the tunnel leading to the stone buildings, and the other tunnel leading to the path he'd followed when he'd first come in. A few unicorns were talking nearby, but they didn't seem to notice him. Relieved, he made his way toward the tunnel that would lead him out of the cave, but stopped when he heard a shout.

"Mist Morning!" an accusing voice called.

Thorax turned to see another unicorn stallion staring at him with angry red eyes. The unicorn made his way over, the sound of his black stained hooves echoing around the cavern.

"Where have you been?" the stranger growled. "I thought you went to help Golden Comet's team work with the amulets. What are you doing here?"

"I…I…" Thorax began, barely remembering to speak in the voice of the unicorn he was impersonating. "I thought that…the others up there could use my help."

The unicorn didn't reply to his statement, and instead gave him an odd look. "Well, you're sure acting strange today. If you're worried about Canterlot, stop being worried and do something useful. Scarlet is stressed out enough as it is."

"Yes, I will," Thorax replied. "I just need to go up to the surface for a bit."

"Look, do you think this is a game?" the unicorn hissed. "I don't know if you've forgotten, but we're working with a very limited window of opportunity here. If we don't take Canterlot soon, there goes our chance. Comet said you volunteered to help him, so get back there and go to work!"

"Y-yeah, of course," Thorax replied timidly. He stepped away from the exit tunnel and walked toward the one leading to the massive cavern with the buildings, figuring that that one was more likely than any other to lead to this 'Comet' unicorn.

"It's _that_ way," the other unicorn grumbled, angling his head toward one of the other brightly lit tunnels. "Look, I know what's going on, but seriously, get a hold of yourself!"

"Right, sorry!" Thorax cried, darting into the tunnel that the unicorn had indicated. He didn't hear a response.

He went as far into the tunnel as he dared before slipping into a dark side tunnel and crouching down out of sight, not sure how long he should wait before checking if the other unicorn had left. At least, he thought, it seemed like it hadn't even crossed the unicorn's mind that he was some sort of imposter. He had just been angry with Thorax, not suspicious.

Urgency made him decide to leave earlier than he thought was otherwise safe, but when he emerged into the cavern with the connecting tunnels, the other unicorn was gone. He walked to the exit tunnel, forcing himself to move slowly rather than run in order to avoid any attention. As he made his way through the tunnel and toward the light of the sun, he saw his image reflected in the crystal orbs again. At least, he realized, if anypony was monitoring them, it must mean that the real 'Mist Morning' was somewhere away from any of those orbs.

When he emerged into the sunlight, the mare who'd spoken to him before gave him an amused look. "Not talented enough for Comet, huh? I'm surprised he didn't have any grunt work for you."

"I just need a break," Thorax said in response. "I'll just, um…" He thought back to what Twilight had said about teleportation. "I'll teleport back to the tunnel in a bit."

"Hm…" The mare looked to him with something close to irritation, then her gaze softened. "Okay, fine, I won't tell. Make it quick."

With that, Thorax hurried off toward the bushes and trees in the distance.

**-ooo-**

Spike sat with his back against a tree, anxiously watching the others. Twilight was pacing back and forth, Fluttershy was fearfully crouching down in some bushes, and the others were talking quietly together. Spike was growing more worried about Thorax. He hoped his friend hadn't run into any danger.

A figure stepped through the bushes, its pale body and melted-looking horn giving Spike a shock as he let out a small cry of alarm. The ponies in the clearing all turned toward the newcomer.

"It's me!" Thorax said, speaking in his own voice. In a flash of teal, his normal changeling form stood before them. "Sorry about that."

"No worries," Pinkie Pie told him. "It was only terrifying."

"What did you find?" Fluttershy asked anxiously.

"Well, I did find another entrance," Thorax replied. "But I'm not sure where it is in relation to here."

"I can help with that," Twilight told him. "Just describe the area to me and we'll find it."

The six other ponies and the dragon all looked to him confidently.

"All right," Thorax said. "I'll tell you everything I remember."

**-ooo-**

It didn't take long for Twilight to find the area that Thorax had told them about, and, not long after that, they found the cave entrance with the remains of its broken door.

"It's like a maze down there," Thorax warned the others, "but I can lead you to the main tunnels from here." He paused, thinking about the glowing orbs he'd seen in the tunnels. "They have magic crystals though, and I think they use them to monitor all the main tunnels. And…if they saw you…"

"Ugh, well that's just great," Rainbow muttered. "How are we supposed to get around that without magic?"

"Well, there are lots of empty tunnels," Thorax replied. "Some of them connect the main paths to each other. We can try to avoid the crystals until we know where the artifact is."

"That sounds…pretty dangerous," Fluttershy said with a shudder.

"Well, if there are so many tunnels, they can't possibly monitor them all at once," Rarity pointed out. "Especially if so many of these ruffians are at Canterlot."

"That is true," Applejack agreed. "Guess we'll just have to be careful."

"There's something else, too," Thorax said. "One of the unicorns told me that they had a 'window of opportunity' to take over Canterlot. I couldn't ask what he meant without giving myself away, but…"

"Well, we can't just _wait!_" Rainbow cried. "What if they break through Celestia and Luna's protection spells by then?"

"You're right," Twilight agreed. "Did he say anything else?"

"Something about a unicorn named Comet, and working with amulets," Thorax replied. "It seemed really important. Though I'm not sure why they need them when a cursed artifact is giving them power."

"The amulets…could be connecting them to it, in a way," Starlight mused. She turned to Thorax. "Did you see their leader anywhere? Or hear about her?"

Thorax shook his head. "No. I tried to stay out of sight. And the only thing I heard was that she was stressed."

Twilight turned to the cave entrance, watching as Applejack kicked in the remains of the door once blocking it. "Well, we need to go in there, find that artifact, and destroy it." She turned to Starlight. "As soon as we do, and we can use magic again, we teleport everyone out, back along the same path to the Crystal Empire. They'll for sure notice something wrong once their power stops working like it did."

"Right," Rainbow Dash said, clapping her hooves together. "Let's do this."

"Thorax, if you're transformed into one of those unicorns, that might help us get out of some tough situations," Twilight said, and Thorax obliged by turning himself back into Mist Morning.

All nine of them then walked up to the cave opening, feeling its musty, hot air wafting toward them. Spike turned to Thorax, giving him a smile. "Lead the way."

One by one, they descended into the darkness.


	4. Into the Tunnels

**Beneath the Surface**

**Chapter 3 – Into the Tunnels**

One by one, the ponies, dragon, and changeling crept through the narrow tunnel leading deeper into the earth. The hot, sticky air of the caves made the darkness seem even more sinister, and they only had the light from Thorax's horn to see by. Twilight and a few of the others were carrying supplies, their saddle bags seeming heavier in the stifling heat. Thorax, disguised as one of the odd pale unicorns with red eyes, was leading the way. He turned his head toward the others.

"The tunnel widens out up ahead, don't worry," he tried to reassure them, speaking in his own voice.

"Oh-okay," Fluttershy whispered nervously from behind Twilight.

Pinkie Pie, right behind her, patted Fluttershy's back. "Don't worry, we're all in this together. Besides, I brought cupcakes!" She pointed a hoof toward the saddle bags she was carrying.

"This place…" Twilight mused as she walked behind Spike and Thorax, "…it feels so oppressive. It's like I can feel something suppressing my magic. I didn't really notice it above ground, but here…"

"So you feel that too?" Starlight asked from somewhere behind.

"It feels absolutely _dreadful,_" Rarity added. "As if walking into some damp, gloomy cave wasn't bad enough."

"I don't feel anythin'," Applejack commented.

"Me neither," Rainbow Dash said.

"Did you notice anything weird like that when you were down here alone?" Spike asked Thorax.

"I…didn't, no," Thorax replied. "It must only affect those whose magic is blocked."

"Yes, us unicorns," Starlight sighed.

"Well, whether we have magic or not, we've got to do what Luna sent us here to do," Twilight said. Truthfully, the foreboding presence of the magic-blocking spell was more than unnerving her, but she tried to focus on the goal, not wanting the others to get any more unnerved.

Up ahead, Thorax stepped out into the wider tunnel, taking note of the pebbles he'd placed earlier. He backed up to allow the others to come into the tunnel after him, and luckily there was enough room so that they didn't have to walk single file.

"All right, Thorax," Applejack said once everyone was in the larger tunnel, "where do ya think is the best place for us to start lookin' for this artifact of theirs?"

"I'm not sure about that," Thorax replied uneasily. "I know where to find a big cavern with stone buildings. It may be somewhere in there, but…"

"All we have to do is get close and we'll feel the artifact's magic energy. That's what Luna told Twilight right?" Rainbow Dash asked as she hovered near the tunnel ceiling.

"We need to steer clear of the magic crystal orbs they have in the main tunnels," Starlight pointed out. "At least until we can be somewhat sure of where the artifact is."

"True, true," Pinkie replied, nodding her head. "But like Rarity said, they can't monitor them all at once! I mean, come on, who has the patience for _that?_"

"It seemed like they're all linked together," Thorax replied, nervously shuffling his hooves. "So…be careful."

Twilight took a deep breath. "Well, from what we now know, a big part of this place is made up of unused tunnels. If we get close enough to wherever they're keeping the artifact, we'll be able to feel where the magic is coming from. Then we can make a plan."

"Sounds good to me," Pinkie cheerfully replied, trotting forward.

The others followed, Thorax walking ahead to point out the way to the others. Starlight hung back until Twilight started to follow, and kept pace with her. "Twilight," she said, speaking quietly as if afraid that somepony would overhear her, "do you think that Scarlet Rose herself is guarding the artifact? If it's powering their magic enough to keep Celestia and Luna at bay, then…"

"I don't know," Twilight sighed. "But whatever's guarding it, we have to try anyway." Thoughts of being unprepared still nagged at her mind, but she tried to push them away.

As they followed Thorax through the tunnels, they noticed a group of strange plants up ahead. "Ooooh, what's that?" Pinkie Pie asked, pointing a hoof at them.

"I don't know," Thorax answered. "I saw them growing in some of the tunnels earlier."

Applejack tilted her head. "Now, what kinda plants grow completely underneath the ground?"

Twilight stepped closer, inspecting the twirled vines and odd-shaped leaves. "I guess plants like these must have something to do with the ponies down here and their magic. I'd find this fascinating if there weren't more…pressing matters at the moment." She gave a nervous laugh.

Pinkie's eyes widened as she glimpsed a few fruits hanging from the plant's branches. She giggled, leaping towards the plant. "This looks tasty!" Before she could bite into the fruit, Applejack pulled her back by the tail.

"How about you don't, at least until we know what it is?" she said once she'd released the pink pony.

"Agreed. Let's not rush into anything," Starlight added. "We don't really know what is safe and what isn't down here."

"Wh-what else?" Fluttershy repeated, shivering. "You mean there could be-"

"Oh, relax, it's just a plant," Rainbow Dash said, knocking aside some of its branches with her hooves. "And Thorax said that these tunnels didn't look like they were being used. They're not going to worry about us bothering a plant."

"Well, let's hope so," Starlight replied. She then motioned for Thorax to take the lead again.

After a while of walking through near-darkness, Thorax stopped the others. "Up ahead is a place where a bunch of the tunnels connect. There are tons of those round crystals around, but the artifact may be near there. I'll check it out." Dimming the light from his horn, Thorax turned around a corner in the tunnel up ahead and disappeared, leaving the others in blackness.

"He's…not going to be gone long, is he?" Fluttershy whispered.

Spike blew a small stream of flame into the air, giving the others a brief source of light. "He's just going to see if there's-"

Before Spike's light faded, the head of a pale unicorn with red eyes appeared around the corner. Fluttershy stifled a shriek, and Twilight tensed up before she realized that it was simply the transformed Thorax.

"We can't go that way," the changeling said, with obvious worry. He lit his horn again, illuminating the tunnel. "There's a whole group of them in there. I don't know if they saw me. We should try another path."

"Into all the…dark, unknown tunnels?" Rarity asked.

"I don't see any way around it," Twilight said grimly. "I can't feel any source of magic that would tell me if the artifact was near. We'll just have to keep track of where we've been."

"Ooh! Ooh!" Pinkie jumped up and down in excitement. "We could pluck some of our mane hairs and make a trail."

Rarity gave her a look of disgust. "Ugh, never!"

"Wouldn't that just lead anypony who was following right to us?" Spike asked.

Pinkie considered this. "Hmm. Yeah, I guess you're right." She gave a shrug.

"I've just been using pebbles," Thorax explained, pushing a few into a rough circle with his hoof. "I don't think it's that noticeable."

"Good enough for me," Rainbow said, flying off toward one of the side tunnels they'd passed while following Thorax. "Looks like this tunnel's as good as any other. Let's go!"

"Wait a minute," Starlight interjected. "Thorax should still go first. If he sees any of those crystal orbs these ponies have, at least it won't be suspicious if he's detected while he's transformed."

The others agreed and Thorax took the lead again. They went through several tunnels, some of them untouched natural cave tunnels, and others that had been mined at some point long ago. The cave air was so hot and stifling that they were quickly growing tired and thirsty. They had to stop to rest a few times so they could each take a drink from the supplies they'd brought. During their journey, Thorax saw a few well-used tunnels lit with the round crystals but felt it was too risky to try to sneak past them. Instead, they stuck to the abandoned tunnels, waiting for any sign that they were closer to the artifact.

"Okay," Twilight mused as she walked behind Thorax, squinting at a small notebook she held in her hoof, "if I've been keeping track of things right, the big cavern with the buildings that Thorax saw earlier seems to be in this direction-" She pointed her hoof toward the wall. "-So that should tell us where to turn next in order to get closer to the inhabited areas. Or at least…a general idea. Some of these tunnels make so many turns. And we don't want to get too close."

"I think we're going to have to," Starlight said, clear reluctance in her voice. "No matter how powerful this artifact is, we haven't been able to feel any of its magical influence just wandering these abandoned paths."

"You're right," Twilight said. "I'm just wondering what the best way to-"

"This way's no good," Thorax called out to the others, interrupting Twilight's thoughts. The disguised changeling appeared from the tunnel up ahead, shaking his head at the others.

Rarity heaved a sigh and sat down, too exhausted to care about the dust and grime. "Well, we might as well just walk into one of their main tunnels, because we certainly aren't getting anywhere at this rate."

Spike turned to Thorax. "Do you think there's any way we can disable those crystals in the tunnels?"

"I…I don't know," Thorax replied. "I was afraid to try in case they noticed…"

"Ugh, well, like we've said before, they can't monitor every tunnel at once," Rainbow said. "Let's just take our chances with one of their main paths. It's the only way we're going to get close enough."

"Hang on a second," Applejack responded. "Let's see if Thorax can check it out first and see if there's anythin' he can do about the crystals."

The others looked at Thorax, who looked nervous, but he nodded. "I can try that. But not up there." He motioned toward the tunnel he'd just come from. "It looks like they're patrolling it, or something. But let's find another tunnel. All the ones with lights probably lead back to that big cavern with the buildings."

"Good idea," Twilight said. "There was one back that way."

They backtracked quickly, passing the smiley face that Pinkie had made with pebbles which marked another tunnel that sloped downwards. Thorax crept into it while the others waited, following the light until he reached the point where the tunnel met a much wider, well-lit one. There was nopony else there at the moment. Quickly he retreated and relayed the news to the others.

"I'll see what I can do, and I'll try to be back soon," he promised, before turning around and heading back down the tunnel toward the faint glow of the crystals.

After a few moments of silence, Spike nervously turned to Twilight. "You don't think they'll…realize what he's doing and get mad, right?"

"If anything goes wrong, we'll be right there," Twilight reassured him.

More minutes of silence passed while they waited in near-darkness, before Fluttershy quietly asked, "What is that?"

The others paused, listening, until they heard what were clearly hoof-beats down one of the other dark tunnels.

"They've found us," whispered Fluttershy, backing up toward Twilight.

"Wait. This place echoes. We don't know for sure where that came from," Applejack said, trying to sound reassuring.

Spike remained silent, noting that the sound of the approaching stranger was growing steadily louder. From somewhere down one of the connecting tunnels they'd explored previously, he heard rocks shifting. He edged his way toward the tunnel leading to the lit passage, where Thorax had gone. Spike stuck his head inside. "Thorax?" he said, as loudly as he dared. "_Thorax?_"

Stones shifted from the tunnel behind them, and they heard somepony step out into the open. Spike felt something rush past him, causing him to lose his balance. Before he could register what happened, a gust of wind blew overhead, and he heard Rainbow Dash shout, "Wait!"

Without thinking, he ran after the shapes of two ponies and down into the tunnel leading toward the light. Now, he could see the silhouettes of Rainbow Dash and Fluttershy. Rainbow was halfway down the tunnel, holding the terrified Fluttershy back. Spike came to a stop, wondering if he should stay to help them or run back up to the others.

Fluttershy gave a shout as she suddenly found herself slipping on the loose rocks. Before Rainbow Dash could lift Fluttershy into the air, her momentum pulled Rainbow forward and they were both sent tumbling down the slope into the crystal-lit tunnel.

"Are you okay?" Spike called down to them, grimacing.

Rainbow winced as she rolled from her side back onto all fours, glancing over at Fluttershy, who seemed momentarily stunned. Shaking her head to get her mane out of her eyes, she looked across the tunnel at the rows of crystal orbs lining the walls. She quickly noticed the transformed Thorax up ahead, on his hind legs with one of his front hooves on the thin bit of metal that held the crystal to the cave wall as he examined it.

He turned to look at them in surprise. "What are you-"

Several flashes of light appeared in the tunnel, replaced almost instantaneously by the forms of pale unicorns. Three stallions, two mares. Each of them looked furiously at the forms of Fluttershy and Rainbow Dash. They did not speak, they did not even approach before firing spells at the two pegasi.

"Wait! Stop!" Thorax cried.

Rainbow Dash gripped Fluttershy and sped sideways through the air, feeling the bursts of energy behind her as the spells struck the cave floor. Almost immediately, more were being fired their way, and Dash zipped through the air, avoiding the bright streaks that lit up the cave like fireworks.

Twilight and the others suddenly burst through the tunnel that Rainbow and Fluttershy had tumbled from. The cave-dwelling unicorns were momentarily startled, a few of them even backing away, until one of them shouted, "They have an alicorn with them!" At once, Fluttershy and Rainbow Dash were forgotten as all five of the pale unicorns rushed toward Twilight, sending their spells straight at her.

Twilight took to the air as bursts of magic collided with the floor and cave walls. Starlight and the others moved to stand in front of the enemies, trying to shield Twilight from their attacks.

"Please," Fluttershy, now flying on her own, pleaded. "Can we just-" She was interrupted by a stray spell that flew close by, sending her retreating to the ground with a shriek.

A sixth unicorn, which had to be the one they had heard approaching in the dark tunnels, appeared from where the main group had just come from, looking just as surprised as the others. Seeing Twilight, however, he quickly jumped into action along with the rest of them.

"Stop! Please stop!" Thorax shouted in a panic, running up to the nearest stallion, who was lighting his horn for another spell. Thorax pushed him aside and the spell was fired into the ceiling.

"Get out of the _way,_" the unicorn hissed at the changeling, roughly shoving him. "If we capture this one, we won't need to bother with Canterlot."

"…What?"

"They're probably here because of Celestia!" one of the mares shouted at Thorax, who just looked horrified. "Don't you get it? Help us!"

As her friends began having trouble keeping the unicorns at bay, Twilight kept near the ceiling, using her flight to her advantage. There were fewer spells being fired directly at her; her companions were doing a good job of keeping the unicorns distracted. She wanted to help them, but every time she tried to get close, their enemies would focus their efforts on her.

She heard a harsh kick and a cry of pain from one of the stallions, and through the chaos, she saw Applejack racing away from a unicorn that was crumpled on the cave floor in pain. "Twilight, get outta here!" Applejack shouted.

Twilight was too busy trying to keep out of range of the spells to shout a reply. She couldn't get a close view of what was happening, but her friends were clearly putting themselves in danger trying to protect her, and she wasn't sure if she could do anything to help. At least the cave guards were outnumbered, but that wasn't a very reassuring thought, knowing the power of the magic they possessed. She could feel the start of a panic rising inside her; they hadn't even been in the cave for more than a couple hours and things had already gone horribly wrong.

In the midst of the chaos, where all of Twilights friends were either trying to fight off the unicorns or protect others, Twilight saw Rainbow dive down toward a stallion that had Fluttershy pinned beneath his hooves. Before she could strike him, she was hit by a spell coming from her left and tumbled to the ground. There she lay unable to move, her eyes looking frantic as they darted from side to side.

"Twilight, go!" Rarity shouted.

Twilight couldn't even see Rarity among the confusion, but she heard some of the others shout in agreement. The realization that the unicorns of the caves wanted her for their gruesome task, possibly even in place of Celestia, fully sank into her frantic mind. If she stayed there, more of her friends could be harmed, but if she led the unicorns away, then maybe the others would have a chance to escape. And she knew she couldn't help Rainbow Dash – or anyone else – if she was captured.

Still reluctantly, she turned away from her friends and flew off down the tunnel. Seeing that she was escaping, several of the unicorns sent spells shooting her way. One of them hit her saddle bag and sent it flying against the wall, but Twilight managed to steady her flight and dart into a dark side tunnel. Three of the six unicorns forced their way past the others and followed the alicorn.

A fourth tried to chase after Twilight as well, but Rarity noticed and stuck out her hooves as he rushed past, tripping him. As he struggled to his feet, Rarity tried to launch another kick at him, but was pulled away by magic toward a furious unicorn mare. The unicorn fired another spell at Rarity, leaving her lying unmoving on the ground just like Rainbow Dash was.

The mare stepped closer to Rarity, only to leap with a cry of shock and whirl around to see the small dragon, obviously the culprit behind the painful burn on her leg.

Spike backed away as the unicorn walked toward him, clearly having momentarily forgotten Rarity and the struggles of her two remaining companions. Out of the corner of his eye, Spike saw the unicorn who he recognized as Thorax. The changeling seemed to have been all but ignored by the other unicorns during the struggle, unable to do much to help the others without revealing himself as an imposter. At the moment, Thorax's eyes were wide with fear as he glanced from Rarity to Spike; he seemed frozen.

"You're going to wish you hadn't done that," the unicorn mare told Spike in an eerily calm voice as she lit her horn again.

At the edge of his vision, Spike saw Thorax shake off his fear and run toward them. Spike wanted to scream at him to stop, to not give himself up, but before Thorax reached them and before the unicorn's spell fired, somepony else got there instead.

Starlight slammed into the unicorn threatening Spike, sending her spell shooting off into the ceiling, where it broke apart pieces of the rock and left a hole in the ceiling. Starlight glanced at the smoking remains as small pieces of rock fell down into the tunnel. "Spike, get out of here!"

"But-" Spike began, and a shout from further down the tunnel interrupted him. Fluttershy and Pinkie were trying to lead one of the remaining unicorns away from a fallen Applejack, though it didn't seem to be working. As much as she could while being frozen from the spell, Applejack tried to urge them to run. Fluttershy's eyes brimmed with tears, and she and Pinkie hesitated a moment before running off. Spike realized the whole effort of fighting these unicorns was fruitless; the only reason they'd lasted so long was because of surprise and numbers. Now they had neither.

"Come on," Starlight said, pushing Spike toward a side path up ahead with her hoof. "If we let them pick us off, we can't help the others!"

Deep down, Spike knew she was right, but he hated to turn away from the three friends who had been struck down with spells. At least they seemed physically unharmed; perhaps these unicorns wouldn't be as quick to hurt a pony as the furious mare had been to try to hurt him. He climbed on Starlight's back, knowing she could run much faster, and she galloped toward the relative safety of the nearest dark tunnel.

Thorax watched them leave, his breath coming in gasps as he fought back an increasing feeling of panic. Then one of the cave unicorns, no longer having any moving targets, turned to him angrily.

"Don't just stand there! Follow them! We'll deal with these ones." The stallion motioned toward the three ponies lying still on the cave floor.

"But I- What are you going to-"

"If you have a problem with any of this, you can take it up with Scarlet." the unicorn shouted. "Now go bring some of the others back. You have a job to do."

Fear, as well as knowing that giving away his true intentions would not help his friends, made Thorax turn away from the unicorns and run down the tunnel, heading into the gloomy side path that Starlight and Spike had disappeared into.

Once he was gone, the three remaining unicorns turned their red eyes to their captives. "How in Equestria did they get in?" one muttered.

"I think the more important question is why – and how – they brought an alicorn with them," another said.

"This changes _everything,_" the third added.

The three unicorns lit their horns and teleported themselves and the three captives away, leaving the tunnel empty.


	5. Separated

**Beneath the Surface**

**Chapter 4 - Separated**

Twilight finally stopped in the darkness of one of the tunnels, sure enough that she had lost her pursuers in the long, labyrinthine passages. However, she had also become lost herself.

The alicorn stood alone, exhausted from her frantic flight and aching from where she had been scraped by rocks or the jagged edges of walls as she fled. Her only source of light was the faint glow of her horn, and even that took all her effort to keep up. She let the light fade, deciding to conserve her magical energy while she thought about what to do next.

The darkness that settled over her when the light went out was enough to make her shiver, despite the heat. She couldn't make out anything, but at least she didn't have to use what little of her magic that could push through the cave ponies' spell. She lay her head down on the warm stone ground, trying to make sense out of everything that had just happened.

Unless the others had managed to stop them, the unicorns now had Rainbow Dash. Maybe the others, too. Thorax hadn't seen enough of the cave to have any idea of where they'd take prisoners, and even if he had, she had no way of talking to him, and no way to know whether or not he had been found out. What could she do? She was the one the cave unicorns were targeting. They clearly thought she was a good enough substitute for Celestia to try to retrieve the second artifact.

She thought about finding her way out of the cave, getting help from the Crystal Empire, and leading them back to find her friends. But would there be enough time? She couldn't just leave the others there while she escaped. Who knew what these ponies could do to them?

She knew her choices were to wait there, to find a way out of the cave and get help, or to find a way to reach her friends herself and come up with a plan. Out of those three, the last one seemed like the best option, or at least the only one that didn't make her feel terrible and helpless, but Twilight had no idea where to start. She was lost, and for all she knew, her enemies were probably still lurking in the black tunnels. Trying not to let her worried thoughts spiral into panic, she took a deep breath.

"Okay…" she whispered to herself, as quietly as she could. "Just think. Where to go from here…?"

She couldn't just barge her way back into the well-worn paths these unicorns used; they were, apparently, monitored well at all times, unless she and her friends had just had a particularly bad bit of luck. At least, she thought, nopony looking through the crystal balls had seen her specifically among all the chaos; there would have been dozens more unicorns teleporting to the spot if that were the case. However, the ones that _had_ seen her were bound to spread the word, so she supposed it didn't matter all that much in the long run.

Lost in her thoughts, she paced back and forth in the tunnel. "Okay, maybe…wait, maybe I can-" Then she paused, her brief hope fading. "No, that won't work. But what about…no..." It seemed futile; every plan she could think of had a glaring flaw.

"They'd just teleport the moment they…" She paused. From the moment she'd flown into the dark tunnels, none of the three unicorns pursuing her had tried to teleport ahead of where she was flying. Teleportation spells were difficult, and she imagined that teleporting while in darkness, into a narrow tunnel they probably didn't know well was even harder. Risky, even. There. That was one flaw the cave unicorns had, even underground. It wasn't much, but it was something, at least. And since a lot of them were at Canterlot, there probably weren't as many able to teleport to random tunnels at a moment's notice. That was something else.

"That still doesn't leave me with much," she sighed, thinking back to each of her friends and wondering where they were now. Surely at least some others had managed to escape and were wandering the unmarked tunnels like she was. Should she go to find them, or stay where she was in case they wandered her way? Perhaps she could write a list of the pros and cons of each and work it out.

As she lit her horn, she remembered with dismay that the saddle bag she'd brought was gone, along with her notebook, pencils, food and water. Depending on how much time they might spend down in the caves, maybe waiting wasn't an option.

The sound of shouts echoing from somewhere close made her jump, and the light from her horn faded. Ponies were yelling – and it certainly didn't sound like her friends – but due to the cave's echoes she couldn't quite tell which direction it was coming from.

Then, further up ahead, she saw a light, faint but getting closer. She tensed, realizing that the cave unicorns had almost found her again, but this time, it sounded like there were more than three voices.

In a panic, she lit her horn just enough to see by and raced into a side tunnel.

**-ooo-**

"Well, it's dark. There's nopony around…and we're not sure where Twilight is," Pinkie mused, her eyes wide as she glanced around the blackness. "Yep, this is pretty much awful."

She heard a quiet sniff and turned around, moments before another pony headbutted her in the dark. "S-sorry, Pinkie," followed Fluttershy's voice. The pegasus sounded on the verge of tears.

"Oh, it's all right," Pinkie said in her usual cheery voice. "And just 'cause everything's awful doesn't mean we can't turn it around."

Fluttershy responded with only another sniff.

"Well, um, just look at what's around us! I'm sure we could make use of something." She tapped her hoof against the rock wall. "Now, there's rocks…some ceiling rocks…oh, and those weird plants that we-"

"I can't see _anything,_" Fluttershy responded, her voice sounding even more distraught.

"You know, you've got a point there," Pinkie replied, but her smile fell when she heard the quiet sounds of Fluttershy's sobbing.

Pinkie stepped closer, careful not to run into her in the darkness. "Aw, don't worry. Twilight and the others have gotten out of worse situations than this. We'll find them!"

"I just…wasn't expecting everything to go wrong so fast. And I panicked and I couldn't help the others."

"It's not your fault, Fluttershy," Pinkie replied. "And remember, this isn't over yet! Those unicorns are gonna feel pretty silly once we escape. Oh, and I have cupcakes! That'll cheer anypony up!" She rummaged around in her saddlebag for a moment before saying, "Hm…they're kind of smooshed, but I'm sure they taste just as good!"

Fluttershy sighed. "Thanks, Pinkie, but not right now."

"All right," Pinkie replied, shoving the smashed cupcake in her mouth. "Well, we better start looking around for the others." Pinkie began walking ahead and called over her shoulder. "Just be careful where you step!"

Fluttershy kept her wings close to her body as she followed the sound of Pinkie Pie's hoofsteps. She tread carefully, jumping whenever she heard the sound of a rock shifting or a strange echo.

"Hold up!" Pinkie shouted from up ahead. "My tail's twitching, so I think we'd better…"

Fluttershy gasped as Pinkie suddenly backed up into her, and a loud thud was heard up ahead as a large rock crashed to the ground. "Wh-what was that?"

Pinkie walked forward and felt around the rock with her hooves. "These old tunnels are kinda…crumbly. But my Pinkie sense is there to help!"

"We're not safe here in the dark…" Fluttershy whispered.

"Hmm…" Pinkie mused, glancing around. "Ooh! I think I can see something up there. Though I'm not sure."

"What?"

"See? There?" Pinkie replied, taking a moment to locate Fluttershy and try to turn her in the right direction. "It looks like there's some light down there, reeallly far away."

Fluttershy squinted her eyes, peering into the darkness until she noticed what Pinkie had seen. Faintly, in the distance, there was a tiny pinprick of dim light reflecting off a cave wall. "You're right. I…guess we should at least get closer and see what it is, in case…"

"Let's go," Pinkie cried, bouncing ahead.

"Careful!" Fluttershy warned as she cautiously moved forward, feeling the ground in front of her with her hooves.

The two ponies headed down what turned out to be a fairly narrow tunnel until they reached the turn where the faint light illuminated the cave wall. Around the bend, they realized that the tunnel led out into a much bigger cavern, one that was nearly dark. Nearly.

They crept forward, peering out into a cavern that dwarfed anything they'd seen underground so far. If the ceiling were higher, Twilight's castle could have easily fit inside it. Parts of the cavern were lit up by the same round crystal lights as in the other parts of the cave, but these lights were at a fair distance away from where their small tunnel had led out, and many of them looked to be coated in dust and grime, dimming the glow.

The most notable thing, however, was the massive structure built around two stone pillars. It had no distinct shape, being a mishmash of different sheets of metal and in some places blocks of stone crudely put together. Glowing orbs – these cleaner than the others in the cavern – were positioned all over it seemingly randomly, and the light reflected off the metal, giving it an eerie look. They could see some brighter lights behind and to the side of it, and realized there were well-lit tunnel openings next to the structure.

"Whoa…" Pinkie gasped, stepping forward from the tunnel.

Fluttershy jumped as some kind of bang sounded from inside the structure, and a hiss of steam leaked from a rusty pipe leading from its "roof" into the cave ceiling. "We…we shouldn't go near that," she whispered.

"What in Equestria _is_ it?" Pinkie asked, not seeming nearly as worried.

"I don't know, but this doesn't look like a safe place," Fluttershy replied.

"But what if they keep their artifact in there?" Pinkie countered. "You know, to throw us off? Like, we'd think they'd keep it in some fancy-shmancy cave room with powerful crystals or something, but no! Instead, they keep it in this dirty run down shed! It's the perfect conspiracy!"

"Well, I think we-" Fluttershy began, but broke off as an angry shout sounded from the metal construction. She quickly urged Pinkie to duck back into their tunnel with her, just as a crude door in the structure opened and a unicorn strode out.

Like the others, this one was pale with black markings, her body having a tint of green, but she wore a sort of helmet over her head that shielded her eyes. With a frustrated growl, the unicorn levitated the helmet off and tossed it to the ground. Her eyes were the same bright red as the other unicorns they'd seen.

"Jade!" the angry voice from within the structure shouted again, this time clearer thanks to the open door.

"Cool it, will you?" the unicorn shouted back. "I've been working all day. I'll clean the mess up when I get back." Ignoring any further shouts, she made her way toward one of the bright tunnel entrances.

On the way, she glanced over the tunnel Pinkie and Fluttershy were hiding in and turned toward it. "Huh?" she said, her eyes peering into the darkness. "Who's there? Is this a joke?"

Fluttershy had no idea how they'd been spotted but figured these ponies must have sharpened eyesight from being underground so long. She crouched lower to the ground, watching the stranger in terror.

The unicorn levitated over a small lantern that easily detached from the makeshift building. She held it in front of her with her magic as she walked closer to where the two mares were hiding. "If you still think this is funny, _now_ of all times, then you've-"

Just as Pinkie and Fluttershy were trying to quietly back into the tunnel, the unicorn appeared at its entrance, the light swinging in front of her and revealing the two ponies. Her eyes went wide as they stared at her in shock; she seemed just as horrified to see them as they were to see her.

Pinkie was the first to snap into action. "Here, have a cupcake!" she cried, reaching into her saddle bag and flinging one of the smashed treats into the unicorn's face.

The unicorn cried out in surprise, flinching back and dropping the light she carried.

"Run!" Pinkie cried, racing back into the tunnel.

Fluttershy took a moment longer, snatching the lantern by its handle before she turned and ran after Pinkie.

"Intruders!" the unicorn cried from the tunnel entrance as she wiped cake frosting off her face, not following the two ponies in but clearly trying to alert the others. "Some ponies got into our cave! They may be working with Celestia!"

"What's all the noise for?" an older mare said, walking out of the metal structure.

"Two ponies from the surface were here," the first unicorn answered. "Get me another light and I can go after them."

The older unicorn, however, did not seem surprised. She walked toward the younger one, levitating the helmet she'd thrown to the ground earlier and none-too-gently placing it back over her head. "You've got a job to do, Jade. Get back in the workshop. The others will deal with this."

The younger unicorn made a sigh of frustration and stormed back toward the door. The older one then motioned to another two ponies who were exiting the same doorway. "I want you to send a message. Tell the ponies monitoring the crystals to keep an eye on all the tunnels they can, especially those that connect to any abandoned ones."

"But, there are so many," said one of the unicorns. "They could be hiding anywhere. With everyone searching for the intruders, there aren't enough of us left to monitor everything-"

"Find any of them if you can. But they have an alicorn. That's the one who's important. That's what we're really looking for."

**-ooo-**

Starlight and Spike came to a halt when they were sure they weren't being followed by anypony other than Thorax. They'd also come to a stop because their tunnel led out into a huge, open (but thankfully empty of any unicorns) cavern, that they could only see due to a strange type of glowing moss lining the walls, trailing down in places. Spike stepped down from Starlight's back and immediately let himself collapse to the floor, exhausted after what had happened.

Starlight was trying to catch her breath, frantically checking for any sign of an enemy. "Spike…you alright?"

"_I_ am," Spike said after a few moments, "but they…they got Rainbow, Applejack, and Rarity." He sadly looked down at the ground. "I guess I wasn't much help."

"None of us were prepared for that," Starlight replied, still breathing heavily. "But we'll find them. We'll…figure out something."

They both looked up at the sound of hoofsteps and Thorax, still transformed into a pale unicorn, arrived. "Are you okay?" he asked, his voice frantic as he rushed up to them. "They didn't hurt either of you, did they?"

"Yeah, we're okay," Starlight said. "Rarity, Rainbow, and Applejack were captured, and they may have gotten others, but I think Twilight probably escaped." She noticed the terrified look in the disguised Thorax's eyes, and added, "They didn't look hurt. The spells just disabled them. I don't think these ponies really _want_ to cause unnecessary harm."

Thorax shook his head. "They tried to hurt Spike! And who knows what they'll do to the others. We have to do something. We can't let them hurt them!" Teal light engulfed Thorax's body, revealing his normal black chitin form. He was shaking, and breathing more rapidly. "They almost hurt Spike, and if they find us-" He stopped, starting to hyperventilate.

"Thorax, I'm fine," Spike told his friend, but in spite of the reassurance, Thorax couldn't calm down. Spike looked worriedly at the changeling. He had never seen Thorax this way.

Starlight had. She moved closer to Thorax, putting a hoof on his shoulder. "We'll figure it out. They didn't seem to care that we ran off, so they probably aren't hunting down the others right now…" _'Except Twilight…'_ she thought, and realized that wasn't much of a comforting statement. "And, well…nopony realized that you were a changeling. We've got that going for us."

"Yeah," Spike agreed. "We can still use that."

Several minutes passed as Thorax gradually began calming down. However, he still seemed shaken up. They could see him trembling in the dim light of the luminous moss.

Starlight took a deep breath. "I think…what we should do is…to look for any signs that any of our friends have been near here." She turned her attention to the large cavern just outside the space they were resting in. Thanks to the luminous moss, she could see quite a ways ahead, where other caverns and tunnels connected to the large one. There was no sort of pony-made lighting; it looked abandoned. "We need their help. And we won't go too far looking. We'll just look around the tunnels and see if we can find something."

"Like what?" Spike asked.

"I don't know," Starlight said, scrunching her eyes closed. "Some of our friends had supplies, maybe they dropped something. Or there could be mud with hoofprints that are fresh. I…"

Spike glanced down at the ground, realizing as much as Starlight did that the plan was a long-shot. Yet like her, he didn't know what else to do. "Well, we know there's a path the cave unicorns use back that way…" He pointed down the tunnel they'd followed to their current spot. "So we can't go back there." He turned to face the large, gloomy cavern. "Guess our only option is to wait here or go forward."

"Well, let's take a look around," Starlight said. "If it seems safe, let's wait here. If any of our friends show up, we can spot them easier in an open area. A lot of tunnels lead out into this place."

"Good idea," Spike said, before turning to his other friend. "Thorax?"

Thorax still looked on the verge of panic. "Okay…" he replied, his voice still shaky. Spike wasn't sure he had paid much attention to their conversation.

"How about…" he began, realizing that Thorax was not currently in any condition to help them. "How about me and Starlight look around the cavern and you stay here?"

Starlight glanced to Spike before nodding. "Yeah. We won't be far, and we'll stay within earshot. If something happens, we'll find each other. Just take a moment to rest and calm down. Don't worry, we won't be very long."

"You're gonna be fine," Spike added, giving Thorax a reassuring smile.

"If you hear anypony coming, disguise yourself and come find us," Starlight said.

"And if we hear anypony, we'll come find you," Spike added.

"Are you sure about this?" Thorax asked, looking from Starlight to Spike.

"We really won't be gone long," Starlight promised. "We just want to check it out. We'll be careful. We'll try to stay within sight of this tunnel. We'll see what we can find, and then make a plan if nopony shows up."

Thorax nodded, and the others called some encouraging words to him as they left. Then Starlight and Spike were carefully walking out into the large cavern, Thorax watching nervously from the tunnel entrance.

**-ooo-**

One by one, Rarity, Applejack, and Rainbow Dash were ushered into a cell built into the cave wall itself, the metal bars at the front the only thing that wasn't rock. They had been teleported into the huge cavern with the buildings that Thorax had told them about, and within a few minutes, the paralysis from the spells they had been hit with had worn off. Unfortunately, their captors had thought to stop Rainbow from flying, and put a weaker version of the spell on her wings to immobilize them.

They had been led past the buildings, where a few curious onlookers had stared at them in silence, then down a tunnel and to a wide cavern with a relatively low ceiling. From there, they were taken to one of several cells.

The moment the three ponies were inside, the barred door slammed shut by one of the unicorns' magic. A moment later, bright streaks of light, like small bolts of lightning, flickered and jumped over the bars.

Rarity lifted her hoof as she looked at the grimy stone ground in disgust. "Ugh, really? You couldn't even have the decency to put us in a dungeon you bothered to _clean?_ I mean, you've had plenty of time down here to-"

The stallion who had taken the lead while they were brought to the cell stomped his hoof into the ground. The two others who had come with him walked up to stand in front of the cell bars, staring at the three captive ponies. Rainbow Dash bristled, gritting her teeth as she fought against the paralysis spell to unfold her wings. Applejack stared defiantly at their captors. Rarity narrowed her eyes.

"You know, it wouldn't kill you to at least be a bit more polite and show some basic decency if you're going to force us to stay here."

The stallion ignored her statement. "You brought an alicorn in here with you. Who is this pony? Where did she come from?"

Rarity and Applejack glanced nervously at each other.

Rainbow rolled her eyes, acting calm and nonchalant. "Psh, you thought that was an _alicorn?_ I mean, I can understand making the mistake. Guess your crystals don't have an accurate-"

"I _saw_ it with my own eyes," the unicorn growled. "So did they." He gestured to the unicorns on either side of him. "You're a bad liar."

"In all that chaos?" Rainbow replied. "Are you _sure?_"

The unicorn gave her a sort of annoyed glare, then turned to one of his companions, whispering something in her ear. She gave him a knowing look and trotted off, vanishing around a corner.

"What was _that_ for?" Rarity asked.

"You'll find out," was the only response she got.

"_Finally,_" Rainbow said, and Rarity turned to see the pegasus stretching out her wings, showing off the fact that the simple spell on them had worn off. The two unicorns standing guard didn't seem amused, but they didn't make a move to stop her as she flew a couple laps around the cell.

"I'll have you know," Rarity began, turning to the guards again, "we are very important in Equestria, and Celestia would _not _be pleased if you harmed us in any way."

"I see," the stallion said, unimpressed.

"I'm serious, we-" She paused as she noticed Applejack motioning at her to stop talking. She suddenly realized that giving them that sort of information was not a good idea.

Further talking was interrupted as the unicorn mare returned, levitating a bottle of some strange-looking potion. The three captives felt immediately uneasy as the guard who had been talking to them levitated it over the rest of the way with his own magic.

"Any volunteers?" he asked.

"Eugh," Applejack said, making a face. "There ain't no way we're drinking that who-knows-what."

"Really?" the unicorn replied. "I think you are. And how about you be the one to try it?"

Applejack suddenly found herself being pulled toward the front of the cell by the stallion's magic. The spell held her in place as the unicorn forced her to drink some of the potion.

"Don't use too much," said the mare who'd retrieved the bottle. "We won't need it to last more than a few minutes, and the ingredients for this potion are hard to find."

The unicorn pulled the bottle away from Applejack, who looked dazed but otherwise unharmed.

"Applejack? Are you okay?" Rainbow asked.

"Physically I'm fine, but nothin' about this situation is okay!" Applejack responded. "We've been captured, Twilight an' the others are still out there and Celestia knows what's happened to them. Speaking of Celestia, if we don't find a way to destroy that artifact, she and everypony at Canterlot are gonna be in a huge amount a' trouble."

"Huh?" Rainbow responded.

"Applejack," Rarity whispered. "This is probably not a good time to go saying those things."

Applejack acted as if she hadn't heard. "Twilight's magic can still work down here a bit, but it's hardly enough to get us through all the obstacles in this place, and-"

Rainbow quickly covered Applejack's mouth with her hoof, but the unicorn guards only smirked.

"Tell us about this Twilight. Is she the alicorn we saw?"

Rainbow cried out as she was dragged away from Applejack and toward the other end of the cell by magic. Rarity watched worriedly, conflicted and contemplating what to do.

Applejack's ramble about the cave's obstacles stopped abruptly. "Twilight is our friend, the Princess of Friendship, and one a' the Elements a' Harmony. Last night, she was visited by Princess Luna in a dream, and was told of the attack on Canterlot, which-"

"Luna?" the female guard repeated, looking to the other two in surprise. "You mean Luna's…returned?"

Rarity and Rainbow Dash glanced at each other from across the cell. So they really hadn't seen Luna when they'd attacked Canterlot. If they had, the news was bound to have spread to the unicorns still in the cave by now.

"Luna returned as Nightmare Moon," Applejack continued, her voice flat and emotionless. "Together, my friends and I, including Twilight, were able to stop her and return her to her normal form. Luna now rules alongside her sister, Princess Celestia."

"Are there any more alicorns?" the stallion asked.

"Yes," said Applejack. "Princess Mi Amore Cadenza, known to us as Princess Cadence, rules the Crystal Empire. She recently had a daughter, Flurry Heart, who is also an alicorn."

"The Crystal Empire?" the third guard asked, giving the other stallion a confused look.

"That's where we were stayin' when this all happened," Applejack said. "Cadance is married to Twilight's brother, Shining Armor, who-"

"Is _he_ an alicorn?" asked the stallion, looking just as shocked as his companions.

"No, a unicorn," Applejack replied.

"That still means that there are two other alicorns in this 'Crystal Empire,'" the mare said, turning her red eyes to the stallion. "We could always use a backup plan if this 'Twilight' isn't strong enough. Though the baby alicorn is too young, we could wait if we absolutely had to."

"_What?"_ Rarity gasped. "You would even kidnap a foal for-"

"What are the Crystal Empire's defenses, and where is it located?" the stallion interrupted.

"The empire lies to the north of here," Applejack explained. "Your cave is between it and Canterlot. The empire is protected by the crystal heart, which keeps away the blizzards that ravage the north, and has protected the empire's citizens from enemies such as Sombra. Sombra was-"

"I don't care," the stallion snarled. "Tell me where this crystal heart is."

"The crystal heart is kept beneath the castle in the center of the empire," Applejack replied.

The female cave unicorn grinned. "I'm betting that any protection spell they make would be easier to take down than Celestia's if we remove this 'crystal heart.'"

"That is true," the stallion mused. "If the alicorn who's found her way down here fails, we can focus our effort there." He turned to the other stallion. "Let Scarlet know."

The stallion nodded, lit his horn, and teleported away.

"Applejack, what are you doing?" Rainbow shouted, despite knowing deep down that Applejack wasn't speaking of her own will.

"I'm tellin' them what they wanna know," she replied.

Rainbow Dash gritted her teeth and flew up to the front of the cell. "You're sick, you know that? You're just gonna sacrifice the lives of every alicorn you find until one of them manages to do what you want? Do you have any idea what-" Her words were suddenly cut off as she flew too close to the electricity-like magic jumping over the bars. With a cry of shock, she was flung into the back wall of the cell and then crumpled to a heap on the ground.

"Oh, my- Rainbow, are you all right?" Rarity asked, running up to her as Rainbow muttered a few frustrated words in response.

"Do you have an idea where Twilight is now?" the stallion asked Applejack, ignoring the other two. "Is she still in the cave or would she have fled?"

"She oughtta still be here," Applejack replied. "I'm not sure where, but she wouldn't abandon us and she knows Celestia and Luna are countin' on us to destroy the artifact that is givin' y'all your power."

"Go spread the word," the stallion said to his mare companion. "I'll keep watch over them here."

As the mare left, the dazed look in Applejack's eyes faded away. She shook her head, looking at the stunned Rainbow Dash and Rarity in confusion. "What the… Can somepony tell me what just happened?"

Seeing that the stallion was not going to oblige, Rainbow rose somewhat shakily to her hooves. "They gave you some sort of truth potion," she said. "And it worked."


	6. Take Her Place

**Beneath the Surface**

**Chapter 5 – Take Her Place**

Twilight ran frantically through the cave's mazelike passages. She had managed to evade her pursuers for a time, but they weren't as clueless about the unused tunnels as she and her friends had hoped. When she had the chance, she used her wings, but most of the tunnels were too small or had ceilings too low for flying to be much of an advantage.

There were more unicorns chasing her now than there had been earlier; from the shouts she could hear at times behind her, it sometimes sounded like half the unicorns left in the cave were following her. She was often left with little time to choose a new route, and many times was forced to leap into random tunnels in the hope it would throw off at least some of the unicorns following her. Fear of reaching a dead end weighed heavily on her mind with every turn.

She reached a path that split off into two tunnels, and without much time to think, she chose the smallest one. At least if they followed, they could only follow one at a time. With her wings pressed close to her body and her horn lit up enough just to see a few paces ahead of her, she charged onward, trying to ignore her ever increasing exhaustion.

Dim lighting from up ahead got her attention, and for a moment she panicked, thinking her enemies had cut her off. But then she realized that it wasn't moving closer, and as she ran on, the tunnel widened out, the ceiling no longer so close to her head.

It was time to use her wings.

Twilight spread her wings and soared toward the ceiling, trying to keep as close to it as possible. Glad for the chance to give her legs a break, she risked a glance over her shoulder.

That was when she saw the head and front hooves of one of the unicorns charging toward her out of the darkness. He fired a spell at her, which she barely managed to dodge. He was getting ready for a second shot, but luckily Twilight saw that up ahead, the tunnel opened up even wider. With all her might, she sped forward.

**-ooo-**

Thorax lay with his head between his forelegs as he stared into the gloom of the massive cavern in front of him, the eerily glowing moss lighting up the stone formations. He couldn't see Spike or Starlight from his position at the moment, but he knew that if they shouted, he would hear them.

His panic had mostly subsided, but instead he just felt exhaustion in its place. He could not stop thinking of what might be happening to his other friends, or where in the cave they were at that moment.

A beam of light flashed through the gloom, brightly illuminating the further side of the cavern before it struck the ceiling with a boom. Thorax jolted upright, peering out of the tunnel opening to try to get a glimpse of Starlight and Spike.

Before he could spot them, more lights appeared at the far end of the cavern, where a large opening served as a 'window' into another open area. A pony darted through it in the air, barely ahead of where the beams of magical light were striking. The light of the spells was much brighter than the glowing moss, casting enough light for him to recognize the fleeing pony.

It was Twilight.

Alarmed, Thorax took to the air to get a better view, watching as Twilight vanished beyond his vision, and a group of white unicorns thundered after her, not noticing him at his distance. He froze, only his wings beating, as his first thought told him that he needed to find Spike and Starlight. But another part of him told him to run to Twilight's aid.

There were lights coming from a few other tunnels on the other side of the cavern. He could now see Starlight and Spike racing back toward him, looks of terror on their faces.

Thorax knew they couldn't leave Twilight to be caught by that furious group of unicorns. But what could they do? What could _he_ do? As thoughts raced through his mind, he thought of something.

Trying to summon his courage, he looked toward Spike and Starlight, knowing they'd probably also seen Twilight and the unicorns run by. Teal magic engulfed him, and it when it vanished, he looked like an exact copy of Twilight. Giving Spike and Starlight a look of determination that he hoped masked his fear, he sped across the cavern and into the tunnel Twilight and the unicorns had gone.

Flying through the wide cavern Twilight had run through, Thorax kept his gaze fixed ahead. The sounds from the chase echoed in the tunnel and made it difficult for him to tell how far ahead Twilight's pursuers were. He could see some lights in the near distance. It seemed like fewer spells were being fired, and he hoped that Twilight had managed to lose them. He tried to gather more courage as he sped toward the light of the spells. No matter what happened, they could not capture Twilight. Starlight had said that they might not hurt the others, but the purpose they wanted to use an alicorn for would kill her. If there was anything he could do, he couldn't let that happen.

As he approached the unicorns, he heard commands being shouted. They were approaching two different tunnels and one unicorn was shouting at the group to split up. Thorax knew that no matter which tunnel Twilight had entered, the unicorns were bound to find her quickly.

Thorax lit up his horn with teal magic and fired a weak spell in the direction of the running unicorns. Several of them turned around, and when they discovered the source, their eyes went wide. "The alicorn's back there!" one cried. "She can still teleport!"

"There's no way-" the one who seemed to be leading the group began, but as she turned around, she spotted Thorax and her mouth dropped open. "What in Equestria…_turn around!_" She raised her voice loud enough so that all the unicorns in the group heard. "Everypony, back this way!"

The confusion that followed as most of the unicorns fought to reorganize themselves in the small space gave Thorax the time he needed to speed off in the direction opposite of where Twilight had gone. Within seconds, however, the group of unicorns was racing after him, every one of their horns lit.

"Keep her in your sights!" the mare, now at the back of the group, shouted. "Don't let her fool you again!"

As Thorax flew down the tunnel, he noticed with unease that it narrowed the further he got. One of the unicorns fired a particularly far-reaching spell that zoomed past his feathered wingtip. They could still see him, and as long as they could see him, they wouldn't suspect that Twilight was somewhere else.

As the tunnel got narrower and the ceiling lower, Thorax was soon forced to tuck his wings to his side and run. He could hear hoofsteps pounding behind him, sounding like they were getting louder. Did these unicorns ever get tired?

Thorax emerged from the small tunnel into a larger area with several connecting passages. He had no idea which one led where, but he had no time to think. He swerved into a tunnel to his right and continued running.

When the unicorns emerged from the small tunnel entrance shortly after, they quickly split up, a small group going in each tunnel.

**-ooo-**

The unicorns had all raced after the transformed Thorax, but none of them had noticed that Spike and Starlight were watching from the darkness of the larger cavern. The sounds of the chaos quickly faded further away, leaving an eerie stillness in its wake. Were it not for the distant shouts and the marks left by spells on the walls near the tunnel the unicorns had just run through, it would have seemed like nothing had happened.

Feeling like she'd finally caught her breath after the dash across the cavern, Starlight stepped closer. "He just-"

"They were after Twilight, so Thorax distracted them," Spike responded, echoing Starlight's own thoughts. He turned to Starlight frantically. "Who knows what they'll do if they catch him and find out! We have to go after them!" He grabbed one of Starlight's forelegs and tried to pull her toward the entrance to the large tunnel.

"Wait!" Starlight exclaimed. "We need some sort of plan. We can't just run after them or they'll-"

"I'm not leaving him alone with them!" Spike protested, and before Starlight had a chance to object, he let go of her hoof and began running toward the tunnel.

"Spike!" she shouted, realizing immediately that she'd said it too loudly. Spike made no response, so she ran after him. She reached the edge of the opening into the tunnel as Spike vanished from view.

"You!" a voice shouted, coming from somewhere behind.

Starlight whirled around, seeing two more unicorns climbing out of a small tunnel. They looked to be alone, which was some relief, but without her magic, Starlight didn't think she could hold her own against them.

She couldn't lead them toward Spike. She didn't want to split up, but she could think of nothing else to do. Spike was in enough danger as it was. And she was sure she could lose two unicorns in the tunnels.

Without a word, she turned and darted across the cavern, jumping up onto some rocks to reach a higher tunnel opening. She climbed inside it as quickly as possible, wanting to put as much distance between herself and the unicorns.

She needn't have bothered. As the two unicorns approached, they noticed the telltale spell marks and signs of commotion in the big tunnel before they reached her.

"Look at all this," one said. "They had to have chased the alicorn this way. Forget the unicorn, she can't do any damage without magic. I want to be part of the group that brings Twilight back."

The other unicorn agreed, and they headed into the tunnel, following the most recent spell marks.

By the time Starlight realized she wasn't being chased, she also realized that she wasn't sure of her way back.

**-ooo-**

Thorax sped through a winding tunnel, not daring to look back. He could hear shouts and hoofbeats, but he had no idea how far behind his pursuers were. He brightened the light coming from his false alicorn horn, hoping that they were still following him and that they hadn't somehow stumbled upon the real Twilight again in the maze of passages. He had no idea where he was going, or what he planned to do, all he could think of was leading them away from Twilight, away from the one whose life they were planning to take.

He reached a longer section of tunnel that simply sloped downwards instead of twisting. He charged down it, and when he was halfway across, the tunnel lit up and he ducked to avoid a spell that seemed like it had been fired from a longer distance.

Maybe they were getting tired, he hoped. That couldn't help with their aim or spellcasting ability. He focused his attention on the way ahead, where the tunnel curved again and he could briefly put a wall between him and the closest unicorn. He felt the ground beneath his hooves tremble as he rounded the corner, looking around for his next path to take.

He ran right into an open area with unicorns blocking every exit.

Thorax skidded to a halt, realizing that there was nowhere to run. The room was larger than the tunnels, but the ceiling still low; he couldn't fly his way out of there. Without thinking, he started to back up, only to hear a spell hit the ground behind his hind legs. He glanced over his shoulder to see a line of unicorns standing in the tunnel behind him. He turned back around to realize that the horns of every unicorn guarding the exits to the room were lit.

In the center, a mare stood as if she'd been waiting for him. "So," she said, stepping forward as magic sprung to life around her own twisted horn, "this is the 'Princess of Friendship?'"

Thorax crouched down. Terror washed over him, the adrenaline from the chase quickly wearing off. "Are…are you Scarlet?" he asked, in Twilight's voice.

"No," the mare replied. "But she'll be happy to see you." She stepped closer to Thorax, examining his transformed body. "It's fascinating, isn't it? New alicorns springing up out of nowhere. And you're so young, too." She paused to look at the cutie mark on his flank. "I assume this means that you're a gifted magic user?" She smirked. "I don't know how you and those ponies and the dragon got in here, but you had the sense to stick to tunnels that made teleportation difficult, and you did a good job of tiring us out. So, we'll let Scarlet and Comet deal with you."

A stallion stepped up next to her, his gaze threatening. "You're coming with us, Twilight. Do not open your wings, and do not use any magic." He angled his head toward one of the other tunnels, which Thorax now realized led to a path that glowed with light from the crystal orbs he'd seen in many of the tunnels. The unicorn in front of that path stepped aside. Thorax was pushed toward the center of the room, where all the pale unicorns gathered around him, ready to cast spells at the slightest sign of resistance.

Thorax felt his fear rising. Whatever the consequences of his choice were, he was about to face them. "Wait…where are we-"

"Just come with us," the mare leading the group replied. "We're walking there. If you can run through all those tunnels, you can handle a walk." Looking around at the unicorns, Thorax figured most of them were too tired for a teleport, but not too tired to stop him if he tried to flee.

Shaking, Thorax was forced to walk amongst the group of unicorns. He hoped that wherever Twilight was, she was far away from here. And that somehow, his other friends were able to find one another, and to find the artifact, or at least a safer place.

**-ooo-**

Spike had realized quickly that Starlight wasn't following him. The thought filled him with dread, as he knew that splitting up was a bad idea, and he didn't know if she was in danger. Had some of the shouts he'd heard been coming from back in the mossy cavern where Starlight was? He had no idea how to tell. He wanted to go back, but he was sure Thorax was in more immediate danger. The stone walls around him were marked with spells that had missed, some of them having singed the stone and were made visible by remnants of glowing moss. Even if the tunnel split up ahead, he had a path to follow.

Hoofsteps sounded behind him, and he felt a surge of panic. He darted behind a rock near a wall, watching as two other unicorns thundered past. Where had they come from? They were running from the direction of the moss cavern, so he feared they had come across Starlight. Spike briefly debated what to do. He again decided that Thorax was in bigger danger, so once the unicorns' bodies had faded into the darkness up ahead, he got up and followed them. As he did, he grabbed a small bit of the moss from the wall so that he would have something to see by when the tunnel got darker up ahead. He had to find and help Thorax. If Thorax was willing to put himself in danger for Twilight, Spike could do the same for him.

**-ooo-**

Thorax had been led through various well-lit tunnels, often attracting the attention of other unicorns in the larger areas. At one point, he'd seen a few small foals peering at him from the entrance to another bright tunnel, but they were hurriedly shooed away by a couple of the adults. Thorax had thought they'd be heading to the underground city he'd glimpsed while first exploring the tunnels, but they had passed it by and he only got a quick look at the buildings through some openings in the tunnel wall.

Instead, they forced him to walk until they came to a large set of metal doors built into the end of the tunnel. A unicorn at the front of the group rang a bell hanging near the doors, and they all stood and waited. Thorax was terrified, but he knew that for the sake of Twilight, he needed to keep up the charade.

The doors opened, revealing the entrance to a chamber larger than any Thorax had seen so far. He was aware that many of the unicorns surrounding him were pointing their horns straight at him as he was made to walk through the doors.

Thorax found himself looking around the cavern. It was lit by the same crystal orbs he had seen in other areas, though most of the light was clustered around a space in the middle, which was surrounded on most sides by tall rocks that had been carved into shelves. Beyond that, Thorax could see immense stone pillars that spanned the height of the cavern, lit up faintly by the orbs near them. He couldn't see any other entrances or exits aside from the door he'd just been brought through.

He was forced to march forward over uneven, rocky ground toward the brightly lit spot in the center, where he could see a unicorn sitting in front of what he realized was a very large version of a crystal orb. As they approached, the unicorn turned from it to look at them, not seeming surprised in the least.

One of the unicorns leading Thorax dipped her head politely. "Golden Comet, we've found her."

Thorax found himself crouching toward the ground as the unicorns backed away from him, leaving him in clear view of the new unicorn. He couldn't stop himself from shaking as Golden Comet stood up and made his way over. Unlike most of the others, Comet was taller and bulkier than the ponies Thorax was used to, maybe even more so than the Crystal Empire guards. His pale coat had a faint yellowish tint.

"Very good, thank you," Golden Comet said, turning from Thorax to the gathered group of unicorns. "I will see that you're all rewarded."

"Where is Scarlet?" one asked.

"She will be here, don't worry," Comet replied. "Now, I want a few of you to wait by the door. The rest can wait outside."

"But, Comet, the alicorn's wings-"

"We can handle it," Comet said dismissively, waving a hoof. He focused his attention on Thorax again. "Princess, come here."

Thorax wasn't given a choice, however, as Comet's magic gripped him and pulled him forward. When he reached Comet, the magic abruptly released him, and he fell forward, scrambling to catch himself with his hooves.

"Now, listen here," Comet said in a whisper, leaning his head down toward Thorax. "If you cooperate, we'll let your friends go. We have no use for them. But _you,_ you could be the answer we've been looking for."

"Wh-what do you want me to do?" Thorax asked, his voice still replicating Twilight's.

"Scarlet will show you," Comet simply replied.

Thorax found himself gripped by Comet's magic again, and he was dragged forward toward the large crystal ball sitting in the center of the area. He was stopped and then held in place right in front of the giant crystal, Comet beside him.

There was a flash of light, and another unicorn walked around the crystal orb into view. This mare was also tall, though not as tall as Comet. Her coat was a reddish white, but unlike the others, her black mane and tail had streaks of orangish-red through them, making them appear like cooling lava.

"Scarlet Rose, here is the princess. This is _real._"

Scarlet approached Thorax, who crouched lower, but was unable to back away due to Comet's magic still having a hold on his legs. The unicorn leader examined him silently, looking skeptical.

"This is a _princess?_" she asked, but there was a hint of excitement and hope in her voice.

"I told you, it's real," Comet replied, using his magic to stretch out one of Thorax's feathery purple wings. "Unicorns can't do this. She has to be new; there were no other known living alicorns before our curse."

Scarlet approached Thorax, her eyes widening as she lightly touched his wingtip with her hoof. "That's no illusion. A new alicorn…I didn't know it was possible."

"Apparently, not the only one. There's two more," Comet explained. "One is just a foal, but the other rules a new empire."

"I heard," Scarlet replied. "I just wasn't sure what to believe…until now." She turned to face the large crystal ball. "Watch closely, Twilight."

The surface of the orb shimmered, and then in the center, an image appeared. It was an artifact made of four crystals forming a diamond, with two more crystals twisted together in the center. Thorax's breath hitched. It was the artifact Twilight had described from her dream.

"This artifact brought a curse upon us," Scarlet explained. "It was found in a part of the cave where many magical objects were buried. However, there is another. One that was said to be paired with this one." The image in the crystal warped, and another artifact appeared in its place. It looked similar to the first, with four crystals in a diamond shape. There were also two crystals in the center, though these were positioned diagonally across, not twisted or touching one another.

"That," said Scarlet, "is what you need to retrieve for us. We'll tell you what to do next once you have done so."

A feeling of horror washed over Thorax. Twilight and Spike had explained to him exactly what that next step was, and he knew that the two unicorns standing near him did not expect Twilight – or him – to survive it.

"Leave any other artifacts you find alone," Scarlet continued. "They won't help you, and may even harm you. Your magic will work in the cave housing the artifacts, but it will be greatly weakened. This is not our doing, but simply the nature of the place itself. Now, follow me."

Thorax suddenly found that the invisible force holding him to the ground was released, and he could move his legs again. He briefly thought of trying to fly away, but with Comet watching him, he knew he wouldn't get far. He cautiously followed Scarlet as she walked away from the crystal ball, past the rock-shelves that Thorax could see were lined with potions and ancient books, and out into a more open area of the cavern. From there, Thorax could now see another set of doors, barely visible in the darkness, at the far end of the room. When he looked at it, a sickening feeling came over him.

However, they didn't make him walk toward the doors yet. Instead, Comet walked back toward the shelves and returned carrying two small bowls. Thorax tensed, wondering if they were going to force him to drink some kind of horrible potion. Comet lowered the first bowl in front of Thorax, and he saw what looked to be ordinary water inside it. He wondered if they had been saving this here for the real Twilight when they caught her.

"There's nothing wrong with it," Comet told him after seeing his hesitation. "The last thing we want to do is harm you."

Thorax hesitantly sat and picked up the bowl. He was very thirsty after the chase through the hot and humid tunnels. He drank from the bowl while the two unicorns watched, still having suspicions about the water, but knowing he didn't really have a choice.

Comet then set down the second bowl, which Thorax could see was filled with strange plants and fruits, including the same fruit he'd seen on the plants growing in some of the tunnels in darkness. He looked up at Comet, momentarily confused. "Why…why are you-"

"Do you want it or not?" Comet snapped at him, looking impatient.

"She has to," Scarlet said. "There's nothing to eat in that cave and you know what happens to the food anypony tries to bring in."

Thorax was still wary of there being some sort of potion or something else in the food, but like with the water, he knew he had no choice. He took a bite of the strange fruit, which tasted odd but not exactly bad. He thought that trying to eat slowly would delay Scarlet's plans for him, and hoped that it would buy a little more time for Twilight and the others to regroup, help the ponies who were captured, and find the artifact.

Comet, however, caught on to what he was doing. "Alright, that's enough," he said, swiping the bowl aside with his hoof and making Thorax flinch back. "I think she's as ready as she'll ever be, Scarlet."

"Are you sure?" Scarlet asked, looking skeptically at Thorax.

"She won't starve," Comet replied. "If it takes more than a day or two, she can come out, and you and the guards will be waiting. She can eat and drink and then try again."

Something like anger flickered across Scarlet's face at the words, but it was gone almost as soon as it appeared. "…Very well." She turned toward Thorax, lighting up her horn. "You, come with me. Comet, ask some of the others to come as well, and tell them they will be rewarded."

Comet nodded in reply and galloped back toward the doors Thorax had entered the cavern from. He watched the unicorn go, wondering how much time he and the others had. At least nopony seemed to be monitoring the big crystal ball; that couldn't be the leaders' job and it had to be there for other purposes.

Comet quickly returned with three intimidating-looking unicorns, and Thorax could see enough of the door he'd come through to see that the rest of the mob who had chased him were still waiting outside. He realized with dread that there was no getting back out that way, and he wasn't sure how the others would find him after they dealt with the artifact.

"Are you sure you're not too tired?" Scarlet asked the three unicorns Comet had brought.

"If she can walk all that way after that run, so can we," one of the mares said, gesturing toward Thorax. "We're here to help you."

The second mare lit her horn and fired a beam of light right at Thorax's feet. As the changeling jumped back, Scarlet turned to him with interest, having noticed a flicker of teal light pass across his eyes.

"Yes, Princess, we know you can still use _some_ magic," she said. "But let me explain something to you. That spell is simple, and weak, and it won't leave any lasting wounds, but it _will_ hurt. This is your warning. Don't make any wrong moves, don't open your wings, and don't try to use magic until you're in the right place."

Thorax fearfully avoided her gaze as he was led by Scarlet and the three unicorns serving as guards to the smaller doors on the far side of the cavern. As he walked, he quickly glanced back to see Comet approaching the open main doors, through which he could see the group of unicorns who had stayed behind. Comet said something to them that was then met with cheers. One of the guards walking beside Thorax then barked an order at him to look ahead, and he quickly turned to look forward again, not wanting to get zapped with the mare's spell. They continued on in silence until they reached the small set of doors.

"Do you think she has enough power, as a new alicorn?" one of the guards, a stallion, asked Scarlet.

"Well," the leader replied, "we're going to find out." Her twisted horn lit up with a purple glow, and the doors were flung open.

Thorax couldn't help taking a few steps back as he stared into a tunnel that gave the illusion that it stretched forward indefinitely. He had no way of knowing how far it really went; the far reaches of it faded into darkness. In the nearest parts of the tunnel, he could see large crystals embedded in the walls, but it felt nothing like the beauty of the Crystal Empire. Instead, looking into the tunnel gave him a feeling of horror and he wanted no more than to run.

Suddenly he was shoved forward into the ground by one of the unicorns, roughly enough that the shock of it nearly jolted him out of his transformation. Fortunately, if any of the unicorns had seen anything in his eyes that time, they did not react.

"You first, Princess," Scarlet said.

Thorax brushed the mane – the mane that perfectly mimicked Twilight's – out of his eyes and shakily stood back up. Despite knowing what awaited him in the tunnel, he thought of the real Twilight, hoping that he was at least giving her and the others a better chance. With so many unicorns having chased after him, maybe there weren't many left to monitor the images sent by the crystal balls in all the main tunnels? At least he could hope.

With his head bowed, Thorax reluctantly walked through the doorway and into the ominous darkness of the tunnel, Scarlet and the three guards behind him. Then the doors slammed shut.

Back near the large set of doors that led into the huge cavern, a small figure watched cautiously from behind a jagged rock, listening as Comet praised the group of unicorns waiting in the tunnel outside. It was some comfort to Spike that a large number of the unicorns searching the tunnels were grouped here, thinking they had captured the real Twilight. However, now Thorax was in grave danger instead.

Spike was grateful for the areas of darkness that shielded him from view; nopony had noticed him slip in through the doors right behind the large group of unicorns when they had first entered with Thorax. The dim lighting and his small size had allowed him to quickly hide.

Spike realized that it would be hard to move further, at least as long as the large group of unicorns were standing right behind the open doorway. He was hiding in the cover of darkness, but in order to reach the doors they'd made Thorax walk through, he would have to leave that cover and step into the light, and he didn't think he would get far if he tried it.

His mind began racing with frantic thoughts. He felt powerless as he crouched behind the rock, hardly noticing his claws gouging scrapes into it. He had tried to come to Thorax's aid, tried to think of a plan once he'd snuck into the cavern, but he had been too late.

**-ooo-**

Twilight wasn't sure how long she'd been wandering the tunnels. She had no sense of time in the underground world. She was exhausted, the cave was oppressively hot, and she was desperately thirsty. She knew there had to be water somewhere in the caverns, but there certainly wasn't any in these small tunnels. Of course, she thought, the unicorns living in the cave would have built all their main living and working spaces around whatever water source the cave had; there was a reason they didn't use these tunnels anymore.

At least, she thought, she had somehow managed to evade the horde of unicorns chasing her. Everything now seemed…quiet. She wasn't sure whether to be worried or relieved about that.

She kept going, putting one hoof in front of the other, until a light up ahead caught her attention. She froze; the light was small and moving, and it had come from around a bend in the tunnel up ahead. She realized with dread that she must have been found again, and darted toward a side tunnel. Then she heard a voice.

"Hey? I think somepony's up there?"

Twilight stopped in her tracks; that was Pinkie's voice. She decided to take a risk and call out. "Pinkie! It's me!"

"Twilight?" the voice called back. There was a moment of silence before, "_Twilight!_ It's you! It's really you!" A pink blur sped toward the alicorn, and Twilight found herself knocked off her hooves as Pinkie embraced her in a hug. "Twilight, you would not _believe_ what we've been through! We all got separated, and me and Fluttershy were lost in the dark tunnel, and I tried to give her a cupcake, but then we kept wandering around which just took _forever._ Then we saw a light, and followed it to this really weird sort of building, only it looked like it was built by chipmunks! Ha! Anyway, we got chased away by a unicorn, and we've been walking around for ages, but at least we have a light this time." Pinkie turned back toward the light, which Twilight could now see was a lantern held by Fluttershy.

"Pinkie, Fluttershy, I'm so glad I found you," Twilight responded in relief. "Do you know what happened to any of the others?"

Pinkie's smile vanished. "No," she said with a shake of her head.

"I saw Rainbow Dash get hit by a spell," Twilight mused. "They might have the others captured somewhere."

Fluttershy set down the lantern she was holding. "What should we do?"

Twilight sighed, getting up and starting to pace around the tunnel. "I'm not sure. Everything's gone so wrong and I just-" She broke off, her eyes widening.

"Twilight, what is it?" Fluttershy asked.

"Do you…feel that?" Twilight asked, peering toward the blackness of a tunnel she had walked towards. She stepped inside and noticed faint light in the distance.

"Feel what?" Fluttershy asked, but as she walked closer, her eyes went wide and she backed up. "That is…that is not something good."

Pinkie Pie came to stand beside Twilight. "Yep. That feels like some not-so-good magic alright."

"So you two can feel it too," Twilight mused. The feeling wafting from the tunnel was very faint, hardly noticeable from the oppressive magic that plagued the entire cave, but what she could notice was…different. Related, it seemed, but different. Like it was the _source._

"The artifact," Twilight said. "It's close. Luna told me that I'd be able to know when I was close because I'd be able to feel its energy. I just never got near enough to-"

"But that has to lead to where a lot of those unicorns are," Fluttershy said with a shudder.

"I dunno," Pinkie replied, "we haven't really run into anypony for a while. Maybe they're all just tired."

"Or…planning something," Fluttershy whispered.

Twilight looked into the tunnel with determination. "One way or another, we've got to get there."

"What will we do?" Fluttershy asked.

"I'll tell ya what we're gonna do!" Pinkie replied, her smile returning. "We're gonna find a way to end this mess and free our friends."


	7. Risk and Consequence

**Beneath the Surface**

**Chapter 6 – Risk and Consequence**

"How are we going to do that?" asked Fluttershy.

"Hmm…" Pinkie began. "Well, a few minutes before we found you, Twilight, we kinda accidentally stepped in front of a few of those glowing crystal things. You know, the ones Thorax said tell the cave ponies where we are? Well, nothing happened, so the cave ponies have got to be distracted right now. Maybe what we need to get you to that artifact is just a little _more_ distraction."

It took a moment for the implication of Pinkie's words to sink in. "Wh-what?" Twilight stammered. "Get _me_ to the artifact? You want to put yourself at risk to-"

"Twilight," Pinkie interrupted, holding her hoof to Twilight's mouth. "You're the one they're after, but you're _also_ the one most able to use magic."

Twilight sighed as Pinkie lowered her hoof. "Maybe, but I can't do much with this powerful magic suppressing spell here." She briefly lit her horn to prove it, showing the others that she could only manage a weak glow, rather than an actual spell. "I'm not sure I can do this. And I don't want anypony else in the hooves of these-"

"Twilight, we've got this," Pinkie interrupted again. "We'll stay with you as long as possible while you follow that dark magic to the artifact. Once it's destroyed, none of us will have to worry! So who's with me?"

"Um…" Fluttershy said in a soft voice. "I…are you sure about this?"

"Oh…" Pinkie's voice took on an apologetic tone. "Sorry, Fluttershy. If you don't want to do this, I can go with Twilight alone."

Fluttershy looked down at the cave floor nervously. "No, I'll go with you," she said after a moment. "If Rainbow Dash and the others were brave enough to come to Twilight's aid, I think I can be too."

Twilight looked from one pony to the other. "I…you've both been in so much danger already."

"So what's a bit more, huh?" Pinkie asked with a mischievous grin. "If anypony shows up to harm you, we'll just get in their way and make it a whole lot more difficult."

"Pinkie is right," Fluttershy said, noticing Twilight's doubtful look. "You still have magic on your side, even if only a little. If you find that artifact and stop it, we can find the others and get out of here."

Twilight was still doubtful, and still didn't like the idea of bringing her friends into more peril after everything that had happened, but she had to admit that there wasn't much else they could do. To get to the artifact, she had to take her chances by going through the well-lit and monitored tunnels the unicorns of the cave used frequently. There wasn't any way around it.

"All right," Twilight said, "but let me try to outmaneuver them with flight before either of you risk anything."

"Fair enough," Pinkie said with a shrug. "Let's go! I'm sure the others and everypony back at the Crystal Empire will be dying to hear about this once it's all over."

Twilight felt encouraged by Pinkie's optimism, and as she stepped toward the tunnel with the faint light at the distance, Fluttershy, now holding the lantern again, gave her an encouraging look. Twilight took a deep breath. "Okay. Let's do this."

"Now, that's what I wanted to hear!" Pinkie cheered, charging bravely into the tunnel.

Twilight and Fluttershy quickly caught up with her, racing toward the light in the distance. As it drew closer, Twilight could see for sure that the light was coming from an opening leading into one of the cave unicorns' well-traveled tunnels. The window to the other tunnel was small, however, and when she and her friends came to a stop in front of it, they found that they had to maneuver themselves in awkward positions to wriggle through. Pinkie insisted on going first, and the other two followed.

Then they were standing in the middle of a long tunnel lined with glowing crystal orbs. Twilight flinched as she watched an image of herself and her friends flash through each orb, but after a few moments of tense waiting, nopony arrived.

"C'mon, let's go!" Pinkie urged. "Which way is the magic coming from?"

Twilight closed her eyes, trying to pinpoint the source of the dark hints of magic, but before she could confirm anything, Fluttershy spoke up instead.

"This way," the pegasus stated, pointing a hoof down the right side of the tunnel.

As the three ponies raced across the cave floor, which was smoothed down by careful path-making and the hooves of many unicorns, Twilight felt the artifact's influence growing stronger. She was sure that none of them would need help pointing the way once they reached the next turn. As they ran, all three of them could feel a sense of foreboding coming over them, and even Pinkie's enthusiasm became subdued. Yet they didn't slow their pace, and Fluttershy ran onward with determination, despite her fear.

They soon turned onto another tunnel, then another, and by the fourth one, they realized that the tunnels had started to look more recently maintained; the crystal orbs were more polished and brilliant, and there were no loose rocks on the ground. Then, a fifth tunnel they took opened up into what Twilight could only describe as a small stone city.

The three stopped to catch their breath at the tunnel entrance, realizing that they could see a few unicorns wandering around on upper walkways. Twilight couldn't help but marvel at the structures; they were unlike the buildings she was used to on the surface. Though the buildings were primarily made out of the stones matching the colors of the cave, many were decorated with jewels and crystals. Both the buildings and the cave walls – and even ceilings – around them were covered with lights, both the crystal orbs and other types of lights like lanterns and clusters of glowing crystal formations.

Twilight remembered Thorax mentioning something about a big cavern with stone buildings, and that the artifact may be there. It hadn't seemed like he'd been able to get very close to the city, however. Twilight could still feel the strong magic emanating from the artifact, but it wasn't pulling her toward the main cluster of buildings. Instead, it seemed like it was coming from somewhere off to the side of the cavern, where there were a few tunnel entrances at different elevations with stone paths leading up to them.

"There," she whispered, pointing. She needn't have bothered, though, because Fluttershy and Pinkie Pie were looking in the same direction. It was eerie, the way they could all sense the power of the artifact, getting stronger the closer they got. "Are you ready?"

Pinkie nodded. "Can't see how else we can get there without making a dash for it. Haha! Rainbow would like that one. Um, yeah, I'm ready."

"Yeah, me too," Fluttershy said after setting down the lantern, trying to hide the shake in her voice.

Twilight opened her wings, hoping that if she flew fast enough, her horn wouldn't be noticed. Of course, that would only help if the unicorns walking about the city hadn't been given any sort of description of her. She gripped the handle of the lantern in her teeth.

"Ready…" Pinkie began.

Fluttershy took a deep breath and then opened her wings too, ready to launch herself into the air alongside Twilight.

"Set…" Pinkie shuffled her own hooves, looking out into the brightly lit cavern.

"GO!"

The three ponies burst out of their hiding place, Twilight and Fluttershy soaring toward the tunnels, trying to pinpoint which one had the strongest feeling of dark magic. On the ground, Pinkie dashed toward them as well. A unicorn appeared from around a building, lunged at Pinkie, but she leaped away from him at the last moment, causing him to awkwardly skid into some large containers that seemed to serve as garbage cans.

Shouts from some of the upper walkways rang throughout the cavern, more unicorns gathering there and staring down at the three interlopers. Several of them teleported down to the ground and tried to surround Pinkie, who nimbly dodged them.

Or at least, the first few. The three friends were no more than halfway across the cavern when a group of unicorns appeared around Pinkie, firing spells without warning. Though Pinkie was able to avoid most, she was still hit by two of them, and she collapsed motionless to the ground, just as Rainbow Dash had in their first encounter with the unicorns of the cave.

Twilight turned her head toward the sight, stifling a gasp. She could see Pinkie looking up at her from her position on the ground, her eyes telling her to keep going. Twilight forced herself to look away, focusing on the tunnels that were rapidly approaching. She could feel the magical energy emanating from the center one, about halfway up the rock wall.

Bursts of magical energy zipped past her and Fluttershy as they sped through the air, and a few of the unicorns were starting to use their magic to levitate themselves. But it didn't seem like they could do that and teleport in such a short span of time, so at least Twilight and Fluttershy could put some distance between them. From what she could tell, the only unicorns responding were ones that had happened to be in the city at the time; nopony else was appearing in spite of the crystal orbs placed all over the place. Motioning to Fluttershy with her hoof, Twilight led the pegasus between some of the outlying buildings, hoping for a chance of some cover.

Once they flew between the buildings, there were fewer spells getting close to them for a few precious moments. But then there were unicorns teleporting themselves onto the roofs of the buildings and the ground below, launching blasts of magic at them from different directions. Twilight focused on the sight of the tunnel ahead. _Not far now, just past a few more buildings._

Twilight sped past the structures, and had almost reached the opening to the tunnel when a beam of light shot past her, slamming into the lantern she was holding and causing it to shatter. With a cry of shock, she drew her head back, fumbling a bit in her flight. There was another burst of light, and for a moment, Twilight was sure she'd been struck just as she'd reached the tunnel entrance. But instead, Fluttershy collapsed onto the walkway beside it, her mane and tail spilling over the edge.

"Fluttershy?" Twilight gasped, dropping the remains of the lantern.

The look in the pegasus's eyes was one of terror, but also of determination. With great effort, Fluttershy managed to move her head a small fraction, just enough to tell Twilight that she was trying to motion to the tunnel.

_Keep going…_ Just like Pinkie had tried to tell her.

Hating that she was leaving her friends behind, if only until she destroyed the artifact, Twilight tore herself away and ran headlong into the tunnel. Fighting back tears, she tried to focus only on the way ahead. _'As long as I make it…'_ she thought to herself, _'my friends will be okay.'_

A unicorn teleported a few paces behind her, then tried again to teleport in front of her. She dodged around him, her eyes lighting up as she saw that the tunnel opened up into what looked like some sort of natural grand hall, with a very high ceiling.

Spreading her wings, she took to the air and flew into the open area. There were a few more voices from unicorns in the tunnel behind her, but it was nothing like the mob she had encountered before, and in this place, there weren't any side tunnels for them to split up into and try to cut her off. Just one direction, toward the increasingly overwhelming source of power.

All she had to do was follow it.

**-ooo-**

Thorax's hooves shook as he took step after step down the long, foreboding tunnel that Scarlet and the three guard unicorns were leading him down. It seemed that with every step he took, the sickeningly _wrong_ feeling that clung to everything in the tunnel intensified. He kept his wings – his false alicorn wings – tucked tightly against his sides, remembering the warning he'd been given about opening them.

Behind him, he could hear the three guards whispering nervously to each other, occasionally jumping or even crying out at one of the strange shadows the light from their horns showed on the wall, or a distorted reflection in one of the crystals. Only Scarlet remained calm, not showing any signs of fear as she walked carefully at Thorax's side.

"Something's not right here," the stallion guard muttered under his breath. "Should we turn back?"

"Nothing will harm you if you're careful," Scarlet told him, and only her voice betrayed the slightest bit of unease.

Thorax jumped as he thought he heard something coming from the other end of the tunnel, wherever its_ end_ was. It sounded a bit like voices, though none of it was intelligible. "What was that?" he couldn't help asking.

Scarlet gave him a look he couldn't quite read. "It's nothing."

The stallion guard shuffled nervously. "You're an alicorn. You've got nothing to worry about in there."

Thorax glanced at him, and the stallion was giving him what seemed like a sympathetic expression. He looked conflicted.

One of the mares beside him scoffed. "You were just asking if she was powerful enough. Truth is, we don't know."

"Yes, I know, but they said an _alicorn,_" he said, talking like he was trying to convince himself. "It was always about-"

"Quiet," Scarlet said, and immediately the two stopped talking. "She'll succeed or she'll fail. We'll see what to do then."

"This _needs_ to work," the second female guard said, ignoring Scarlet's request for quiet. "If it does, we can get the others out of Canterlot and won't have to worry about any of that."

"Whether it works or not, it won't be that simple," Scarlet replied, not looking at her. "Celestia won't be happy about this, regardless."

Thorax's breath hitched and he froze. Scarlet nudged him with a hoof, and after some hesitation, he took another step.

"Move it along," growled the first mare guard, a few sparks flying from her horn.

Thorax hurried his pace, trying not to think about whatever lay on the other side of this tunnel, and what he would do once he reached it. As they continued onward, it seemed to him that the light from the unicorns' horns was having less and less of an effect against the darkness, but he wasn't sure if he was just imagining it.

Suddenly a crystal to his left exploded in a burst of light, and he ducked down with a cry of fear. Scarlet nearly slammed into him as she jumped away from the wall.

"What was that?" Scarlet hissed, turning to the guard whose horn was still sparking.

"Sorry…" she said, lowering her head. "I thought I saw something."

"And I'll tell you again," Scarlet growled. "Nothing is going to harm you. Now calm down. You have a job to do."

The unicorn muttered something under her breath as they carried on again. Thorax glanced at the broken crystal, wondering if it had simply shattered easily or if the mare had used a particularly powerful spell in her fear.

They walked for a while in silence, Thorax fighting to keep panic at bay as they got closer and closer to their destination. Then, he saw it. Up ahead, the tunnel opened wider and ended in a massive stone wall. The only way to go further was a crawlspace at the base of it, stretching across most of the wall but much shorter than a pony was tall.

Thorax knew that with every fiber of his being, he did not want to enter that crawlspace. Every instinct was screaming at him to turn and run. Yet deep down he knew that if he did, even if he somehow managed to get away, it would put the real Twilight and himself in danger. He couldn't run. No matter how much he wanted to.

"No magic until you're inside," Scarlet hissed close to his ear.

Slowly, Thorax forced himself to walk toward the dark opening. Scarlet stayed beside him, but the guards hung back. Thorax thought he could hear the sounds like voices again, but he couldn't be sure if his mind was just playing tricks on him after having spent what seemed like ages in near-darkness.

"You can light your horn," Scarlet, still beside him, whispered once they'd reached the narrow opening.

Thorax did so, his horn lighting up with a teal glow. He crouched down to try to peer into the narrow opening, but all he saw was blackness.

"Hey!" cried the aggressive unicorn guard from a ways behind. "She said no magic!"

Scarlet whirled around with an angry look. "Floral Faire, stop-"

The unicorn leader had spoken a second too late. The unicorn guard caught her words just as she fired a beam of bright light at Thorax, who whirled around only for the beam to strike him in the shoulder.

He dropped to the ground, a wave of pain spreading across his body. It was so sudden that he couldn't even cry out; couldn't even breathe. Then it was over. And he was lying on the ground, staring at one of his hole-ridden hooves.

The three guards and the leader were staring at him in shock. Scarlet looked him over, as if unable to comprehend what she was seeing. One of the guards behind her took several large steps backward with a look of disgust.

The guard who'd hit Thorax with the spell walked forward, her fear of the tunnel momentarily forgotten. She stood beside Scarlet, taking in Thorax's fangs, eyes, and legs. "What…is _that?_"

"No…" Scarlet just said, her voice barely above a whisper. It seemed she wasn't even looking at Thorax anymore, but rather right through him.

"Whatever that is, that's not a unicorn, so our magic wasn't blocking-"

"No!" Scarlet shouted, rearing up and slamming her hooves into the floor. "We're going back," she spat bitterly. She turned to look at Thorax, who was still too stunned by the effect of the spell to stand. "Make a wrong move and you'll regret it."

Her horn glowed with a violet light, and suddenly all five of them were transported back into the large cavern where they had begun the journey into the tunnel. Comet was the only one there, going over a book he had taken from one of the rock shelves in the room's center. He looked up as the group appeared, taking in both Thorax and the shocked expressions of the unicorns.

"It was a _fake,_" Scarlet snarled, pushing Thorax forward with her magic. He still hadn't recovered enough to support himself and he stumbled to the ground, crying out. "It's some kind of shapeshifter. This could all be a trick Celestia's pulling on us to-"

Comet's wide eyes looked over the changeling before he shook his head at Scarlet. "No. No, it can't be. The real alicorn is still here. Unicorns I'd trust with my life told me that her friends informed them of her under a truth potion. The real 'Twilight' is here somewhere."

"And why didn't the truth potion get them to talk about _this?_" She waved her hoof toward Thorax.

"Ponies under truth potion answer _questions,_" Comet replied. "But that's not important. We need to regroup. If that alicorn is still here, and we need to find her."

Scarlet turned toward the three guards. "Spread the word. Get everypony watching and searching the tunnels."

"Yes, Scarlet," the stallion said, and the three of them teleported from sight.

Scarlet approached Thorax, who was finally steady enough to scramble awkwardly to his hooves. "Where is the real one?" she asked, but was met with silence. "I know you can talk. Answer me."

"I don't know," Thorax whimpered in terror, taking an unsteady step backwards. Whatever hope he'd had was gone now, and he and the real Twilight were both in grave danger.

Scarlet gave him a disgusted look, then turned to Comet. "Can you have somepony bring more truth potion?"

"There's no point," Comet replied. "The real princess could be anywhere by now."

"See if you can find her," Scarlet ordered, still carefully watching Thorax.

Comet huffed and walked toward the large crystal orb that rested in the center of the cluster of shelves. Different tunnels appeared in rapid succession as he watched the images closely. "I don't see anypony," he began, frustrated. "If any of them were here, those working in the crystal room should have seen-" He broke off, staring at an image of a group of unicorns leading an earth pony and a pegasus down a tunnel. The image changed every few seconds, showing them progressing further.

Thorax's eyes widened; it was Fluttershy and Pinkie Pie.

Comet shifted through more images, but found the tunnels empty. He turned around, looking genuinely alarmed. "That tunnel they were taking those ponies through was leading away from our city," he said. "If they got that far…" More images flashed across the surface of the orb, including one that showed the cursed artifact sitting on top of a stone pillar in another cavern. From his position, Thorax could just barely glimpse it.

Comet walked away from the crystal orb, at least satisfied that the artifact was still in its rightful position. But he was still clearly worried. "If this whole thing was a diversion…" He gave Thorax a brief glance and then turned to Scarlet with a serious expression. "…If they somehow manage to destroy our artifact…" He took a deep breath. "You won't ever be able to fix this."

For a moment, a look of horror crossed Scarlet's face. Then she turned back to face Thorax, the look almost immediately replaced by rage. Realizing that all her fury was directed at him, Thorax shakily backed up as she approached, her horn taking on a bluish-purple glow.

Scarlet's voice was eerily calm. "You just made your worst mistake."

In that moment, Thorax forced himself to move despite his lingering weakness. He took to the air, darting to the side as Scarlet fired a spell brighter than any of the others he'd seen the unicorns use. At first, he felt the wave of magical power surge beneath his hooves, but he barely had time to register that before Scarlet redirected, not even briefly stopping the stream of magical energy, and aimed it upwards, where it struck him across his side.

Unlike the last spell, which had seemed to affect every part of him at once, he only felt pain where it had struck across his right side and foreleg. The pain reached deeper than just the surface; it seemed as if the spell had gone partially through him and was tearing at him.

His vision went black and he fell to the ground.

From partway across the cavern, Spike watched from his hiding place. After most of the unicorns had left the cavern earlier, he had been slowly trying to sneak his way around toward the set of doors they'd taken Thorax to. Before he'd gotten there, however, they had teleported back with Thorax in his true form. And now Thorax had been attacked.

In that moment, Spike forgot about the need for secrecy, or his own safety. Abandoning his hiding place, he ran across the rocky ground toward him. Comet and Scarlet turned away from Thorax and stared at the dragon, but he barely noticed. He reached Thorax's side, and immediately the smell of burned chitin made him want to gag. He could see burn marks on the changeling's right side and front leg, and there were a few cracks in his carapace. He was lying completely still, his eyes closed. Spike knelt down beside him, fearing the worst.

"It's not dead," a voice said behind him.

Spike whirled around to see Scarlet Rose approaching him, her horn glowing. The dragon tensed as she walked towards him, but did not leave Thorax's side.

Scarlet didn't attack, but merely watched him. "If I'd wanted to make it lethal, it would have been." The glow from her horn intensified enough that it gave off heat. "Were you in on this too? Was this your plan all along? To use that creature to deceive us?"

"He's a changeling," Spike said, not entirely sure why he was responding. Scarlet had him trapped, and she knew it. He was powerless to stop her, and at that point he didn't have it in him to try. He turned away from her, back to Thorax again, and in that moment his friend began to wake up.

The changeling only moved a bit at first, his eyes barely opening. "Thorax?" Spike asked, moving around to crouch down by the changeling's head. He paid no attention to Scarlet, who still stood there, watching them.

Thorax's eyes opened wider, a look of recognition coming over them after a few moments. "Spike?" Thorax rasped weakly. "What…are you doing here?"

Another unicorn appeared in a flash of light, not far from where Scarlet was standing. Spike instinctively turned to look, and realized with a jolt that the new unicorn matched Thorax's disguise from earlier. It was the stallion they had seen at the cave entrance that morning.

The stallion looked disheveled and tired. "I'm here with a message," he blurted out, briefly looking over Spike and Thorax in surprise before focusing his full attention on Scarlet. "With everything that happened, there weren't many left to monitor the caves, and somehow the intruders slipped past. I'd just left the workshop when-"

"Slipped past where?" Comet snapped before Scarlet could reply, glaring at the smaller stallion.

"The tunnels…the tunnels they were usually monitoring. It was the princess, the alicorn. Everypony was scrambling…they didn't know until…you see, most of the best magic users are at Canterlot…"

Comet ignored his ramblings, racing toward the large crystal orb in the center of the cavern. With his horn lit, he stared at it as images flashed through it again at a rapid pace. Then he stopped on the picture of a long tunnel. One of his loyal unicorns was racing down it, away from where he knew it led. Then he switched to another image that showed Twilight on the other end, pursued by a group of tired unicorns, almost to the entrance to the cavern that housed their artifact. "What…" he gasped, his expression genuinely shocked.

"I'm sorry," the other stallion said, still sounding shaken. "With the protection spells around the artifact, nopony can teleport directly there-"

"We can get close," Comet interrupted. "Who was left guarding that cavern?"

Scarlet looked uncertain, even _afraid._ "I let most of the guards search for the alicorn because I knew it was safe with me, and then you told me they found her, and-" She broke off suddenly, firing a beam of energy similar to the one she had struck Thorax with straight into the ground, making Spike flinch back in fear. "It's your fault," she hissed, looking toward Thorax.

Spike stood in front of Thorax protectively, but luckily Comet took her attention away from them.

"We need to go. _Now,_" he said to Scarlet as he levitated two short chains from one of the shelves. "We'll keep them here. We need to stop the real alicorn."

Spike felt one of the chains lock around his leg by magic, shrinking to fit tightly around it. The other end of the chain buried itself in the rocky ground. He glanced over at Thorax, seeing that the other chain had locked around one of his back legs. The changeling was pulled away from Spike until he was some distance away before the end of his chain forced itself into the ground. "Stop! Leave him alone!" Spike cried. His shouts went ignored.

"You," Scarlet said to the nervous stallion, who had watched the scene with wide eyes, "find any other skilled magic users that you can. Even if you have to get Jade River and her group."

With that, Scarlet and Comet teleported away. The remaining stallion glanced uncertainly from Spike to Thorax before doing the same.

Spike looked around, relieved that they had somehow been left alone, although the cavern seemed strangely sinister now that it was empty. Spike glanced over at Thorax before he picked up his own chain, breathing flames onto the shackle around his leg to heat it up until it melted enough for him to break free. "Guess they didn't think about dragon fire." Throwing the broken chain aside, he ran over to his friend.

Thorax's eyes were open, but he was still very dazed. He hadn't moved from the position he'd landed in, still lying on his uninjured side even after having been dragged, which made Spike's concern grow.

"Don't worry, we're getting out of here," Spike said, picking up the chain tethering Thorax to the cave floor. Carefully choosing a segment well away from where it attached to Thorax's leg, Spike melted through it like he'd done with his own. Once that was done, he let it drop and moved to Thorax's side again.

"What happened?" Thorax asked, his words sounding slurred. "Where are the others? You shouldn't be here…Scarlet will…"

"She's gone," Spike said, distressed that Thorax hadn't even seemed to have noticed. "Scarlet hit you with a spell but they're all gone. We can get out of here." He looked at the changeling's wounds, knowing they had to be painful but at least they didn't seem incapacitating. There were small amounts of blood coming from the cracks in Thorax's chitin, but it didn't look like anything too serious. "What did she do to you? Can you get up?"

"I think so," Thorax replied with a groan. "Ugh, everything hurts…"

"Okay, we probably don't have much time," Spike said, trying to help Thorax stand up, worriedly noticing that he didn't have much strength. "Twilight's gotta make it to the artifact, and then we can find the others and get out of here." He hoped he sounded more convincing than he felt. _If they caught Twilight…_

Spike kept supporting Thorax as he shakily tried to get his footing, the changeling crying out when Spike accidentally touched a burned area on his side. "Sorry, sorry!" Spike quickly exclaimed, making sure Thorax was steady before he walked on ahead. "Look, I followed the unicorns all the way here. I think I can remember the way back, and we can find Starlight and that'll be-"

He broke off, realizing that while he'd walked ahead, Thorax was struggling just to take a few steps forward. He couldn't put any weight on his injured foreleg, but even that didn't fully explain why his movements were so slow or difficult. Spike moved to go to his side and help steady him again, but before he reached him, Thorax collapsed onto the rocky floor.

"Thorax!" Spike shouted, at his side almost immediately. "What's wrong? What did they do to you? Did you hit your head?"

"No, it's not that," Thorax gasped, gritting his teeth as he doubled over. "It hurts on the inside real bad. It's hard to move."

The dragon watched helplessly as Thorax tried to stand, noticing that he cringed in pain with every small movement. Spike realized that Thorax's injuries were a lot worse than they seemed. However, his wings looked undamaged. "Can you use your wings?"

Thorax managed to get to his hooves, keeping his injured leg off the ground. He tried moving his wings. His left wing fluttered normally, but the right moved a lot slower and Thorax cried out in pain, stopping the movement quickly.

"What's wrong with your wing?" Spike asked, alarmed that flight now wouldn't be an option.

"I think the wing itself is fine," Thorax gasped. "I don't think the muscles that attach to it are, though."

"Can you…transform?" Spike asked, wondering if pegasus wings worked differently enough to allow for flight.

"It wouldn't make a difference," Thorax said, sinking back to the ground. "If I can't use my wings now…I can't in any form."

As the minutes passed, Thorax's pain intensified, Spike realizing that the shock was wearing off. He had no idea what to do; he couldn't get Thorax out of the cavern by himself, and it was obvious Thorax couldn't walk there. The escape that had seemed so close was now out of reach.

Spike wondered if he should try to find the others, or even if he could, but he quickly realized there was no way he was going to leave Thorax alone. He walked over and sat down next to the changeling. "Don't try to move," Spike told him, trying to keep his voice steady. He hoped that if he kept talking, Thorax would be able to focus on him. However, Spike was inwardly panicking, realizing how dire their situation had suddenly become. They were trapped.


	8. Against All Odds

**Beneath the Surface**

**Chapter 7 – Against All Odds**

Twilight was almost out of breath when she finally reached the large cavern. She could feel that the source of the powerful magic throughout the caves was here, drawing her to the artifact. There had been a set of heavy metal doors blocking entry, but, she was able to summon just enough magic to crack them open a bit for a few seconds, just enough to allow her to slip through. She was sure the unicorns following her would have reached the doors seconds after they had closed, but strangely, they did not open again.

Perhaps, she thought, pausing to try to recover from the chase, there was a spell only a few of them who were authorized could use. Yet that didn't make much sense; how had _she _gotten in, if that were the case?

They weren't teleporting into the cavern, either, which also struck her as odd.

Once she had rested for a few moments, she walked forward, taking in the sights of the cavern around her, which seemed deserted. It was large, with a very high ceiling, several odd-shaped pillars of rock reaching from the floor and up into the darkness beyond the reach of the room's many lights. Like many of the other places she had seen, this room was decorated in the glowing crystal orbs, but they weren't the only source of light. There were other crystals, some of them bigger than Twilight herself, lining the walls, floors, and occasionally growing on the pillars themselves. These too gave off a glow, and she wondered if the crystals she had seen in the tunnels and city were made from ones like these.

To her left, quite a distance away where there was less light, she could see that the cave wall had a few big 'windows' into other caverns, though the lighting in them was dim. The furthest window didn't seem to have the same sort of light sources the others did. Instead it was dotted with what looked like thousands of tiny lights that gave off a green tint, and outlined the shape of a massive column. It looked like some sort of bizarre star formation in a night sky. Twilight couldn't really tell how far away it was; her sense of scale was too distorted in the cave.

Despite her worries that something could be lurking in those connected caverns, Twilight turned away from them, walking toward the center of the cavern where she could feel the increasingly overwhelming energy of the artifact's dark magic. In the uneven ground of the cave, she was forced to walk up a steep slope littered with stalagmites, too tired to use her wings yet. Once she reached the top of the slope, the artifact was suddenly in plain sight.

It was resting on a sort of pedestal made of a large stalagmite that had been broken off near the base. Behind it loomed a steep wall of rock that looked like it had frozen in the process of melting. She looked upward, seeing a space at the top where a pony might easily stand, but nopony was there. She turned her attention back to the artifact itself.

It looked almost exactly like the image Luna had shown to her in her dream. Four crystals forming the shape of a diamond, and two more crystals in the center, twisted unnaturally. The magic energy radiating from it was almost unbearable, but Twilight couldn't look away.

She'd found it. Now she had to destroy it.

Twilight knew that she likely wouldn't have much time before the unicorns that had chased her found their way in. Though she was so close to the artifact itself, her magic didn't feel any more diminished than it had in any other part of the cave; this was what the ponies were using to _power_ that spell, and if she could stop it…

With more effort than she'd hoped it would take, Twilight lit her horn, trying to put enough magic into a spell that would at least give her an idea of what sort of things the artifact could resist or not. Her energy draining, she focused only on the spell, and on the cursed crystal object a few steps away from her. Then, when she had summoned as much magic as she could without letting it die out, she fired her spell straight at the artifact.

The bright bolt of magic headed straight for it, but right before it struck the two twisted crystals in the center, the magic suddenly diverted. Instead it shot upwards parallel to the wall of rock behind the artifact until it moved in an arc over the top of the wall and into the dark space above it. Though it vanished from view, Twilight could still see the glow of her spell, as if it had stopped somewhere above the wall and was being held there.

"I heard you coming," a voice said.

Twilight froze, hoping she could summon enough magical energy for another spell, but not wanting to risk trying anything else before she knew who had spoken.

From out of the darkness at the top of the rock wall, a pale stallion appeared to stand at the edge overlooking the artifact. His coat was dull-looking, and even the black patches looked faded. He was tall and thin, and though it was hard to see in the dim light of the cavern, he looked much older than the other unicorns she'd seen. And he showed no worry or fear at finding her so close to the artifact they relied on for so much of their magic.

"I wasn't going to let you damage the artifact," the older unicorn said, "but I wanted to see what you could do. See what your alicorn powers_ really_ were, even despite our spells that would prevent any ordinary unicorn from using magic."

The sound of faint hoofbeats coming from behind made Twilight whirl around. She saw the unicorns that had chased her to the cavern, each of them calmly approaching her. She realized that the only reason she had been able to slip past the door, and they hadn't, was that this unicorn – possibly with help – had allowed it to happen. To give him a chance to see what she could do even under their magic blocking spells.

"We thought Celestia was our only real choice," the old unicorn at the top of the wall continued. "But then you showed up. And you have shown promise. Perhaps this all works out well in the end."

Twilight forced herself to look away from the unicorns that had formed a half ring, encircling her against the rock wall. She hoped that if she kept talking, she could at least buy some time, and think of anything that might somehow help her. "I could have destroyed it," she said, "if my magic wasn't diverted-"

The old unicorn chuckled, looking down at her with a grin. "It wouldn't be so easy. But then again, with new alicorns…you could be full of surprises. Better to keep it safe." His gaze flicked from her to the surrounding group of unicorns. "Disable her magic and bring her to Scarlet Rose."

Though the unicorns that had been chasing her must have spent a great amount of magical energy already, several of them immediately fired beams of light from their horns, the rest charging toward her.

Twilight launched herself into the air, forcing her tired wings to move. She swerved out of the way of a few more spells, avoiding them far too narrowly for comfort. She soared toward the cave ceiling, hoping that at least the distance would make it harder for the unicorns on the ground to strike her, but the blasts of light were not missing her by much. She could avoid their spells for a time by weaving around the stalactites on the ceiling, but she knew she wouldn't be able to keep it up for long. From her vantage point, she could see even more unicorns appearing from the darkness of the cave.

Twilight was so focused on dodging bursts of magic and trying to swerve behind stalactites and other formations whenever possible, that she almost didn't notice the strange, round magical shields clinging to the ceiling and floor where the unicorns' spells had hit.

They looked a lot like a small version of the spells Shining Armor and Cadance had used to protect both Canterlot and the Crystal Empire, and these were certainly big enough to entrap a pony. The words of the old unicorn ran through her mind: _'Disable her magic.'_

The unicorns were firing those shield spells at her, and that could only be because the spells blocked the magic from anypony trapped inside it from reaching the outside. Anypony…or _anything._

She risked a glance down below, seeing the tiny glow of the artifact resting on its makeshift pedestal. She thought back to when she'd tried to fire a spell at it, only to have the spell be diverted toward something else. She figured that if the unicorns wanted to keep the artifact safe, even their own spells would be stopped from accidentally hitting it, and she suddenly had an idea.

Swerving back toward where the majority of the unicorns were gathered, she focused on the tall wall of rock, and the older unicorn standing on its top. Behind him was a faint glow, and as Twilight frantically beat her wings to get closer, she realized that the glow was coming from the remains of her own spell, the weak, fading magic circling around a small statue of a rearing pony.

Whatever it was, Twilight knew that the statue had some sort of spell on it that made it act like a lightning rod for any magic that got too close to the artifact. Her one hope was to be able to grab it.

As she swerved down from the ceiling, the unicorn standing on the ledge turned his head sharply toward her. His face twisted in fury as he lit his horn. But instead of dodging, Twilight dived down faster, his spell shooting past the end of her tail. She reached her hooves out to the magic-absorbing statue, swiping it from the ledge as the tall unicorn lunged at her. Angling her wings, she quickly changed direction and flew straight down toward the artifact, seeing several of the unicorns waiting below ready to cast more magic.

"Stop!" the old unicorn at the top of the wall called to them, but it was too late.

Just as Twilight reached the pedestal bearing the artifact, several beams of light were a mere instant away. Before they reached Twilight, they diverted away from the artifact and around the statue, which Twilight dropped right at the ground in front of the pedestal.

Twilight leaped back as several layers of magical shields materialized around the statue, trapping the artifact next to it within them as well. And at once, most of the oppressive magic in the air lifted.

Twilight felt as if an enormous weight had been taken off her shoulders. Power suddenly coursed through her, her horn lighting with no effort at all. Though she was still physically exhausted, her magic was back, as strong as ever.

"What did you _do?_" one of the unicorns shouted, as he along with many others fired more spells at her.

Twilight quickly summoned a shield of her own to block them, realizing how much weaker they seemed in comparison to just before. With the artifact's power blocked, their magic was diminished, no more powerful than that of regular unicorns.

Twilight turned back to the artifact itself, and stifled a cry of alarm as she realized that the innermost shield around it was slowly starting to dissolve. She froze, thinking of what needed to be done, what Luna and Celestia and all of Canterlot were counting on her to do. Yet she had no idea how to destroy the artifact, and she didn't have long before its magic ate through the magical shields and then the spells that had blocked her power would be brought back to their full strength. She couldn't destroy it, not while having to fight off so many enemies, but she could have time to find her friends and get them out of danger.

Still keeping the unicorns' spells at bay, Twilight lit her horn again to teleport herself back on the other side of the door she'd come from. However, she found herself unable to, and it wasn't because her magic was weak. She realized that even without the artifact's power, there were unicorns here who had made strong enough spells to block any sort of teleportation in this cavern.

Deciding she'd try it again once on the other side of the door, Twilight galloped forward, pushing past a unicorn who was rushing toward the artifact to try to bring down the shields. _'Even if they can get the shields down, it may take them a while,' _she thought. _'Just keep going.'_

Using her exhausted wings yet again, she took to the air and sped toward the doors, flinging them open with her magic. Once in the long, rocky hallway, she tried another teleportation spell, and found that again it failed. But they couldn't have it blocked everywhere.

She wasn't sure how well she could teleport in a place so unfamiliar, but she had to try when she got the chance. Pinkie Pie and Fluttershy had been captured in the stone building city; the cave unicorns were probably keeping them close to that area, and possibly the others too.

She left the hallway, and seeing the lights of the stone city up ahead, she again tried a teleportation spell. This time she materialized at the entrance to the tunnel she had run into after Fluttershy had been struck down.

There were two unicorns down below, looking right at her. She immediately got the feeling that these guys were bad news. Twilight noted the red-orange streaks in the mare's mane and tail, and guessed that she was Scarlet Rose. She didn't know who the large stallion beside her was, but she had a feeling that they were plenty competent with magic with or without the artifact's power.

Twilight quickly teleported herself to the other side of the cavern as soon as she saw their horns light up. To her dismay, the two unicorns appeared a short distance away from her immediately afterward. Twilight fired a spell to stun them, but the stallion effortlessly blocked it.

"Princess…" the mare – Scarlet – said menacingly.

Twilight readied her magic, waiting to teleport away at the first sign of hostility. She didn't have the time or energy to fight two powerful unicorns on her own, and her main concern was getting her friends out before the artifact's power returned. They were all in over their heads.

"Looks like we found the real one this time," the stallion said, a dangerous glint in his red eyes.

"The real one?" Twilight repeated cautiously. _Did they have Thorax too?_

Twin spells shot toward her from the unicorns' horns, and Twilight teleported herself back on the other side of the cavern, trying to get her bearings. Glimpsing a tunnel to her right, she darted into it, only to find herself face to face with a group of shocked-looking unicorns. She teleported back over to the opposite side of the city cavern, relieved to find that Scarlet and the other unicorn were no longer standing there. She saw a bright tunnel leading to a bigger room and focused, teleporting herself into it.

There were _cells_ along the walls. "Fluttershy? Pinkie?" she cried.

"Twilight, is that you?" called a voice from around a corner. _Applejack._

"She was talking to me, silly!" Pinkie said in reply, but Twilight wasn't paying attention to their words as she rounded the corner and found five of her friends waiting in a dimly lit cell. "Hi, Twilight!" Pinkie called, waving. "Welcome to the party! I mean, it's a pretty lame party being in a dungeon at all, but I'm sure you can fix that, and well, at least we're here together."

"Oh, Twilight, I was so worried," Rarity said in relief. "My magic's come back, but whatever spell was put on these bars has proven to be…erm, tricky."

"You can say that again," Rainbow said as she rubbed her head, parts of her mane singed.

"Did you destroy the artifact?" Fluttershy asked from where she was huddled near the wall.

"Not exactly, but-" Twilight began, but a bolt of magical energy struck the wall near the cell, cutting her off. She whirled around to see Scarlet and the big stallion standing in the room several paces from her. Lighting her horn, she tried to teleport both herself and her friends away, but whatever spell was put on the dungeon cell warped Twilight's magic as it moved through the bars, and her friends were instead only teleported to the next cell over.

"Uh, forgive me if you have some sort of plan," Pinkie began, "but, um, how was that helpful?"

Twilight found herself half the room away, thankfully having missed any spells that had hit the ground where she had been standing a moment before. She gasped for breath, her heart pounding. Both of the pale unicorns were gazing right at her. Twilight realized that there was no way to safely get back to her friends and break through the spell on the cell bars while these two were after her. She would have to find a way to lose Scarlet and her comrade, and then come back for the others. Then find wherever Thorax, Spike, and Starlight were. And somehow get everypony out before they ran out of time.

As the horn of the large stallion lit up, Twilight teleported to the entrance of a tunnel leading away from both the dungeon area and the city. Then she opened her wings and darted down it, knowing that the two would be right behind her. She saw a side tunnel up ahead and teleported herself just inside it before resuming her flight.

Her knowledge that time was not on her side – maybe even less so than she realized if the guards in the artifact cavern found a way to bring the shields down faster – made her anxiety grow and she willed herself to move faster. She had to get to the dark, unmarked tunnels. It would be much harder for two unicorns to follow her there. They wouldn't be as familiar with those places, and that, along with the darkness would make it impossible to teleport long distances without risking teleporting themselves halfway into a wall.

The moment she saw a dark tunnel entrance, partially boarded up with rotting wood, Twilight teleported herself to the other side and carried on into the darkness. A shout and the sound of a spell breaking apart the damaged wood a moment later prompted her to fly even faster. Lighting the way with her horn, she turned into one side tunnel and then into the first offshoot that one provided. She made note of every turn she made, making a mental map of her path. As soon as she lost her pursuers, she would free her friends and look for the others.

**-ooo-**

Starlight raced alone through a bright tunnel, ignoring the sweltering heat and her increasing thirst. Mere minutes ago, things had seemed hopeless; she had lost Spike, Thorax had disguised himself as Twilight to lead the cave unicorns away, and she hadn't run into any of her other companions. She had just arrived back at the cavern with the glowing moss, frustrated that she'd only managed to walk in a big circle, when suddenly the oppressive magic blocking her own had been lifted.

All at once, her power had flowed back, and magic came to her as easily as it had before they'd left that morning. Without fear, she had raced down the tunnel she, Spike and Thorax had used to first get to the mossy cavern, and quickly found herself in the brightly lit areas.

Now, Starlight had no fear of the crystal orbs that lined the walls. She had run through several of the crystal-lined tunnels already, facing no opposition. If the crystals were even still sending images to each other, she didn't fear what a few guards could do if they happened upon her. Not with her magic back and theirs weakened. If the spell that had been cast over the caves to block magic was down, that had to mean that Twilight had found and destroyed the artifact. Now they needed to regroup and leave.

Starlight slowed when she heard voices coming toward her, voices that certainly didn't belong to any of her friends. She almost lit her horn in preparation, but spotted a small cluster of rocks that looked to have fallen from the wall quite a long time ago. There was just enough of a gap between the rocks at the base that she decided to crawl into it and hide, waiting to see who was coming.

A small group of unicorns emerged from a larger tunnel. They seemed anxious and stressed. "I told you," a mare said to the stallion next to her. "They didn't mess with our artifact. They were just a distraction."

"Well forgive me for not counting on them having a _shapeshifting bug pony,_" the stallion growled back. "Anyway, it can't heal itself by changing form, or it would have done that already. It – and the dragon – they're not a threat anymore. Somepony said that-"

Starlight's eyes widened at their words, but when the stallion broke off and turned his attention to a small tunnel off to the side, she soon realized why. Twilight herself had appeared, coming to a halt when she noticed the small group of unicorns. Both Twilight and the unicorns in the group lit their horns, but before any of them could strike, Starlight fired a quick spell at each of the unicorns and they dropped to the ground, stunned.

"Uh-uh. Not today," Starlight said as she stepped out of her hiding place.

"Starlight!" Twilight said with a grin, looking immensely relieved to see her. "You're alright!"

"Yeah, more or less," Starlight replied.

"I don't know where Spike and Thorax are, but everpony else is in some sort of dungeon that's close to here. We don't have much time. We need to get them out quickly, and-"

"Wait a minute," Starlight interrupted, noticing the worry that had taken over the relief on Twilight's face. "Didn't you destroy their artifact?"

"No," Twilight replied, looking at the ground instead of Starlight. "I…I didn't know how, and I was getting overwhelmed by the ponies guarding it. I tried to, but…all I could do was temporarily block its magic, and I don't know long that will-"

"Twilight," Starlight said as she put a hoof on Twilight's shoulder, causing the alicorn to stop her musings and look at her, "it's okay. We'll rethink this and see what to do. Right now, we just need to find everypony and get to safety." When she saw Twilight relax a bit, she said, "Do you know where this dungeon is?"

Twilight nodded. "But I don't know where Spike and Thorax went."

"I think they're being held down there," Starlight said, walking over to the group of unresponsive unicorns and peering into the tunnel they'd come from. Now that she had a good look, she could see some openings in the tunnel's walls that showed glimpses of the city. "If the dungeon you saw is near here, we can split up. I'll find Thorax and Spike, you find the others."

"You're sure they're down there?" Twilight asked, giving the tunnel a worried glance.

"I'm pretty sure," Starlight said.

"Okay…" Twilight answered shakily.

"You find your group, and start teleporting back to the Crystal Empire," Starlight said. "I'll do the same."

"If you don't make it out…" Twilight began, "…I'll come back for you, Thorax, and Spike."

"You won't need to worry about that," Starlight responded, hoping she sounded confident enough to mask her own growing worry. "Now, if you said there's not much time, we should go."

"Yeah," Twilight said, turning toward the tunnel that led – according to what Starlight had seen in the windows of the large path – to the city. "Be careful," the alicorn added before she took off in that direction, and Starlight began running down the large tunnel, where in the distance she could see what looked like a massive set of doors.

**-ooo-**

The moment Twilight reentered the dungeon, several guards were waiting for her. Without access to the power from their artifact, their spells were weak enough to glance harmlessly off the shield that Twilight surrounded herself with. She stunned a couple with her magic, but a few others escaped and ran into the city cavern. No time to chase them.

Twilight ran up to the cell where her friends were, immediately taking note of the lightning-like bolts of magic that flickered over the bars.

Rainbow Dash flew as close to the bars as she dared. "Twilight, what's going on? You said you weren't able to-"

Twilight shook her head. "I'll explain everything later. But we need to leave _now._"

Running a list of counter-spells through her head, Twilight tried each one in succession on the bars, none of them having much effect. She quickly opted to use her magic to bend the bars enough for a pony to step through, and managed to move her friends through it one by one using a weak magical shield. Luckily these spells didn't get distorted by the magic on the bars.

Just as Pinkie, the last pony to walk through the mangled bars, stepped through, a flash of light from behind made Twilight turn around. There, standing in the center of the room, were the two unicorns that Twilight knew were capable of putting up a dangerous fight without the use of their artifact.

For a brief moment, Twilight locked eyes with the unicorn who had red streaks in her black mane. Scarlet had a furious look on her face, staring at Twilight like she was prey.

Before the pale unicorns could react, Twilight summoned all the magical energy she could, and she and her five friends vanished from the room.

**-ooo-**

Starlight reached the set of metal doors at the end of the tunnel, flinging them wide open with her magic. As she looked around the vast cavern, the first thing she noticed was a group of odd-looking stone shelves in the center, positioned around a very large crystal ball. She teleported herself over to it, glancing around at the items on the shelves before she got a better look around.

A little ways beyond the crystal and shelves, away from the main source of light, Spike was kneeling down next to a still dark form. Fear flooded through her as Starlight teleported herself right beside them.

Spike jumped with a cry of shock, extending his arms as if to protect Thorax from harm. When he noticed it was Starlight, he lowered his arms, but didn't look much less terrified. "Starlight, we need your help!"

"Don't worry," Starlight said, "we're getting out of here." She looked at Thorax, who was not quite unconscious but was lying on the ground, clearly in pain and unable to move. A short, broken chain was attached to one of his hind legs. He was breathing shallowly, his eyes closed. It was obvious he needed help, and quickly.

Starlight heard shouts coming from the doors she'd left open when she'd arrived. Apparently she'd been followed, but at the moment, she hardly cared. Not even looking in the direction of their enemies, she lit her horn, focusing on Spike, Thorax, and herself as she teleported the three of them away.


	9. To the Castle

**Beneath the Surface**

**Chapter 8 – To the Castle**

Twilight gasped once she and her friends appeared among a group of trees. She had teleported farther from the cave in one spell than she usually would have, being so focused on saving her friends, and the sudden use of so much power made her head spin. "She _knows!_" Twilight rasped, her eyes wide as she tried to prepare for another teleport.

"What?" Rainbow Dash asked, shaking off her momentary disorientation.

"That unicorn," Twilight replied shakily. "I'm sure it was Scarlet. She saw us teleport out. We can't stay here. The artifact's magic will only be blocked for so long." Her horn glowed again.

"Twilight," Applejack said, stepping forward, "we've…we've gotta warn the Crystal Empire too. Those cave unicorns know more than they should."

Twilight noticed that Applejack was looking at the ground, not meeting her gaze. Rarity and Rainbow Dash exchanged uneasy glances. Whatever had happened, Twilight could see that they felt awful about it.

"It's okay," she told them. "We'll do that." Focusing her magical energy, she teleported herself and the group again.

After the next two teleports, Twilight had to pause again. She was low on energy, weak and dehydrated, and she needed a moment to gather her strength. At least they were close; they were standing in the frozen wastes surrounding the Crystal Empire. One more teleport and they would be at the castle.

"Twilight, dear, don't overdo it," Rarity said, seeing the alicorn's exhausted state. "I'm sure we can-"

"I used one of their spells to block the magic coming from their artifact," Twilight interrupted. "The artifact that enhances their power. But it was wearing off. We only have a small amount of time before they get their full power back. And Scarlet and one of her right-hoof lackeys can still teleport without it! If they come after us…"

The other five ponies looked at each other nervously, the harsh north winds whipping at their manes and tails. "Well, in that case…" Rainbow began.

A short distance away, Starlight and her group suddenly appeared. A look of relief came across Starlight's face as she noticed the others, who immediately ran toward her.

"We've got a problem!" Starlight called to them.

"I'll say," Rainbow cried as she fought against the winds to fly toward Starlight. "We need to get to the Crystal Empire and have them put up a protection spell like, _now!_"

Starlight didn't respond, instead gesturing toward where Thorax was lying in the snow next to Spike as the others approached. Twilight's eyes went wide as she noticed the changeling's wounds, and Fluttershy stifled a gasp. The others all looked on with shock.

After a few moments, Thorax opened his eyes, his gaze unfocused as he looked out at the snowy landscape and then up at the ponies closest to him. A look of sudden panic came over him. "Is…everyone out?" he asked, and Twilight wasn't sure if he was talking to her or Starlight. He lifted his head weakly, but didn't seem focused on anypony in particular. "Are they okay?"

"Yeah, but you're not. Somepony needs to find help…as soon as we get there," Starlight said between breaths. She turned to Twilight again. "I just need a moment…then I can take them back."

"What…happened?" Rainbow asked, but Thorax had laid his head back down, looking in no state to tell them.

"I'll explain later, okay?" Spike cried out, sounding on the verge of a breaking point. "Right now, that's not important. We need to get him back!"

"I know," Twilight said worriedly, closing her eyes as she focused on lighting up her horn again.

Though she didn't feel quite ready, Starlight did the same, and the two of them combined their magic to teleport the whole group back to the Crystal Empire.

However, when they arrived in front of the crystalline castle, they were met with a scene of chaos. All around them, crystal ponies were either running or pacing fearfully, and several of their colorful tents that had been set up for the Crystal Faire had collapsed. A group of royal guards was on the ground, trying to reassure the frantic ponies, while another group soared through the air above, as if searching for something.

"Did…somepony crash the party?" Pinkie asked as she looked around at the damaged tents and strewn faire decorations.

"Twilight…" Starlight began, her eyes wide. "You don't think…that spell around their crystal artifact didn't already…"

Twilight didn't respond. Her eyes were focused on the spot just beneath the center of the castle, where a large group of ponies was gathered around. "Where's the crystal heart?"

Twilight's friends went silent, each looking horrified. "Those unicorns…" Fluttershy spoke from where she was sitting beside Spike and Thorax. She had positioned Thorax to rest his head on her leg so he didn't have to lay on the ground. "They…they could still teleport even when the artifact's power was blocked. Like you said."

"And you said the mare was Scarlet?" Rainbow replied uneasily.

"They, uh…they know about the crystal heart," Applejack said, shuffling her hoof on the ground.

A flash of magic moved across the sky far above their heads, spreading out from the top of the castle toward the edges of the empire. Moments afterward, both Cadance and Shining Armor appeared, their horns glowing as they raced toward the newly returned group. Around them, most of the crystal ponies had stopped what they were doing, looking to their leaders and the disheveled group of friends with hope.

"Thorax needs help!" Spike shouted.

Cadance and Shining reached them, their attention immediately drawn to Thorax. Cadance called out to the surrounding ponies. "Everypony, back up! Give him some space."

Shining Armor leaned forward, lighting his horn, and the chain around Thorax's leg unlocked and moved to the side. "We'll do the best we can to help him," Shining told the group, lifting his head again to look over them. "Is anypony else hurt?"

Twilight looked to each of her friends, who were shaking their heads and only had minor scrapes. "No, the rest of us are fine. What…happened here?"

"Not long before you arrived," Cadance began to explain, sounding grim, "a unicorn teleported right here and then away with the crystal heart."

"What?" Twilight said, her eyes wide.

"She was one of the unicorns from the cave," Shining said. "A few of the guards said she was white and had a black mane with streaks of orange and red."

"That's…Scarlet," Spike said.

"We put up a protection spell over the empire right after you arrived," Cadance continued. "But without the crystal heart, it won't be long before the northern storms move over the empire. Our magic can hold our enemies back, but not the blizzards."

"It's not just that," Applejack said. "The cave unicorns know you're here, Cadance. An' Twilight too. Also…" She sighed. "Twilight said that their artifact's magic was blocked, but it wouldn't last long."

"What exactly happened, Twilight?" Rarity asked.

"I'll explain as soon as I can," Twilight answered, her voice growing more frantic. "But we need to make sure the protection spell is strong enough. I don't know if it'll stop them, and Thorax is hurt, and…and we need to protect everypony in the empire."

"Scarlet an' her unicorns would be happy to take _any_ alicorn by force," Applejack continued. "They think the Crystal Empire is an easier target than Canterlot."

"Well, they're not exactly wrong," Rainbow said. At a glare from Applejack, she replied, "What? Celestia and Luna have been around for _ages_ longer than Cadance and Shining have!"

"Scarlet got here before us even without the power-up their artifact gave her magic," Starlight said bleakly. "I'm not sure I want to find out what they can do once that artifact is working properly again." She looked worriedly upward at the shimmering magic shield far above their heads.

"To be honest, I'm not sure how long you can keep the shield up," Twilight told Cadance and her brother. "Luna sounded really worried in my dream. Even both her magic and her sister's won't be able to hold them back forever."

"Wait a minute," Fluttershy said, her voice sounding bolder than usual. "Right before we went into the cave, Thorax said that he'd heard one of the unicorns say that they had a 'window of opportunity' to take Canterlot. Maybe their power _is_ limited, and won't last forever. That might mean…"

"Maybe the magic from their cursed artifact _does_ have an expiration date!" Rainbow finished.

"That…doesn't make much sense," Starlight said. "Why would they wait all this time, just to attack now, if time was so limited?"

"We can't be sure," Shining Armor said. "Perhaps the magic does start to weaken. Why this is only happening now, I don't know, but-"

"If we can just outlast whatever 'time limit' they have," Rarity said, "perhaps we won't need to go after their artifact again at all."

"Or at least not until after the worst of the threat has passed," Applejack added.

"But…we have no idea how long this 'window of time' is supposed to last," Starlight said. "If Luna and Celestia are having trouble, our shields might also only last so long."

Several ponies began talking at once, many of the crystal ponies around them joining in with their own anxious words. Even the guards looked nervous. The chatter continued to grow louder as it seemed like everypony was trying to voice their worries. Twilight suddenly found it overwhelming, closing her eyes as she tried to think, tried to block out the fearful cacophony of noise around her. There had to be something they'd overlooked, some way to keep the ponies of the Crystal Empire further out of danger.

"I have an idea," Twilight said after several moments, silencing the conversations of the ponies closest to her. "Cadance, I know that keeping a protection spell around the entire empire requires a lot of magic. Would it be possible for you and Shining Armor to make a smaller one, over a much smaller area? We could bring everypony there, and that way, you could keep the shield stronger for much longer." Seeing the worried looks of the others, she added, "I know it's not a great plan. But Rarity could be right. If we can outlast whatever sort of time limit they're working with, we can keep everypony safe until this is over. Then we can figure out what to do. And in the meantime, I'll…keep thinking of any other ways we can solve this mess."

Cadance considered her words and quickly agreed with a nod of her head. "We can bring everypony to the castle." She turned to Shining. "Our spell around the whole empire will not be as strong and could have weak points. We need to move fast, before they can make or exploit any such weak points. We can only assume those unicorns will attack quickly and we're not sure what their magic is capable of. And in the castle, we can protect everypony easier, since they'll all be close together."

Shining Armor nodded. "Okay, let's do it." He turned to his sister, who was standing by Thorax and Spike. "Twilight, get Thorax to the castle. The rest of you, start rounding up everypony you can and spreading the word." He glanced over both Twilight's group and the waiting guards and crystal ponies. "Tell them to bring food, warm blankets, and whatever supplies they might need. Without the crystal heart, the storms will be here soon."

"We'll also need help bringing any sick or injured ponies from the hospital," Cadance added. "Starlight, your teleporting abilities can help with that."

Starlight nodded. "Of course. I'll get there right away." Despite her exhaustion, she lit her horn and teleported from sight.

"Fluttershy," Cadance then said, turning to the pegasus. "Can you help round up the animals from the faire?"

Fluttershy nodded in response and flew off toward the area where the petting zoo was kept.

"We're gonna need a lot of supplies for the storms that are comin,'" Applejack said. "I can try an' help the crystal ponies find some."

"I brought several extra blankets," Rarity added. "That'll help at least a few ponies who didn't come prepared for cold weather."

"I stashed my party supplies around the castle," Pinkie said. "So, uh, I'm pretty prepared for any spontaneous parties. I guess I'll just help let everypony know."

"I'll check every building in the empire," Rainbow Dash proclaimed. "Nopony's getting left behind." She sped off, leaving a brief trail of rainbow light behind her.

"Everypony, search and bring as much as you can," Shining called as he galloped toward a row of buildings along the path leading away from the castle. "There are lots of visitors in the empire right now, so try to bring extra supplies whenever possible."

As her friends hurried off despite their weariness, Twilight noticed that Spike had not left Thorax's side. Thorax was still lying weakly and had not moved since they had arrived.

"Can I come with you?" Spike asked Twilight.

"Yes, of course," Twilight answered, trying to give him an encouraging smile. Lighting her horn, she pictured the Crystal Castle throne room, a place where she knew there would be at least a few ponies around who could help them, and teleported herself, Spike, and Thorax there.

The throne room looked beautiful and pristine, quite different from the chaos that had surrounded them mere moments before. Two pegasus guards looked in their direction, and their expressions immediately shattered the feeling of tranquility.

"Twilight?" came Sunburst's voice from the throne room doorway. Seeing the state of the three who had just appeared, Sunburst carefully levitated Flurry Heart's cradle over to the two guards, who stood on either side of her protectively as it was lowered gently to the floor.

Sunburst raced toward the trio, a look of alarm crossing his face as he noticed the state of them, particularly Thorax's injuries. "What happened? One of the guards said the crystal heart was taken and-" He broke off, realizing that none of the three who'd returned to the castle from the cave were in much of any state to explain anything to him. He turned to Thorax. "There's a break room near the kitchen we can bring him to. It'll be a lot quieter there. Then we can figure out what to do."

Twilight nodded, lighting her horn for what felt like the hundredth time since her magic had come back in the cave, teleporting all four of them to a room she recognized that was fairly small. There was a couch on one side of it and a few chairs and a table on the other side.

Too afraid to touch Thorax because of his injuries, Twilight gently lifted him onto the couch with her magic. Sunburst left the room and hurriedly came back with glasses of water.

Sunburst levitated two of the glasses over to Spike and Twilight, who drank from them gratefully. He held the third up to Thorax, who barely opened his eyes, staring at Sunburst with a dazed look. The changeling then noticed the glass of water held in front of his mouth and started to guzzle the water. "No, no, not so fast," Sunburst said, worry evident in his voice. It took a few moments for Thorax to register what Sunburst said and drink more slowly.

"Twilight, what happened?" Sunburst asked. "A few of the guards said the crystal heart-"

Twilight had begun to set her glass down, but before she could speak, Spike interrupted.

"Scarlet took it," the dragon stated, not taking his eyes off Thorax. "Cadance and Shining Armor said that she teleported here, and…teleported back with it. Like it was nothing. Even without the extra power the artifact gave her."

"So, you destroyed their artifact?" Sunburst's eyes lit up with hope.

"No," Twilight said, shaking her head. "I managed to disable it, but…it won't last. Cadance is having everypony in the empire come to the castle. More energy can be put into a magical shield if it's smaller, and-"

"Everypony in the empire?" Sunburst said, the magic around the glass he was holding flickering as he nearly dropped it. "I saw a shield go up, but I thought it was to prevent the crystal heart from being…" His eyes widened. "Are more of those unicorns from the caves coming _here?_"

"They're after me," Twilight admitted. "Or Cadance. Any alicorn. We…didn't know that before we left."

Seeing her distressed look, Spike added, "Thorax found out that, for some reason, Scarlet's ponies only have a limited amount of time before their 'chance' to capture Celestia – or, anypony else – is gone. Twilight thought that if everypony stayed here, we could be safe until that chance is up."

Sunburst looked from Twilight to Spike, trying to take in the information they'd given him. He was interrupted by a cough from Thorax. "You'll have to tell everypony more about that later," he said, before turning back to the changeling. "What happened?" he asked Thorax. "What did this?"

Though Thorax had laid his head back down against the couch cushions, he seemed more alert than he had been before being given the water. "I got hit by Scarlet's spell," he rasped between gritted teeth.

"I saw it happen," Spike said, wanting to take over explaining for his friend. "Whatever that spell did, it was bad. Thorax is really hurt." He looked to Sunburst. "Do you know what kind of spell would do this sort of thing?"

Sunburst looked over Thorax again, his expression uncertain. "There are a lot of spells that can cause injury, but I don't know what this particular one was designed to do. I can't tell how much damage was done just by looking."

"Is there a way to counter these spells?" Spike asked.

"With these types of things, the magic from the spell has already done its damage," Sunburst explained grimly. "There isn't any magic left from the spell to reverse. And healing magic is, sadly, quite limited." Sunburst turned back to Thorax and tried to adjust the pillows and cushions in order to make him more comfortable.

Twilight noticed Spike's hopeful look fade. "They're bringing everypony from the hospital here. Starlight's helping with that right now," she explained. "When they get here, there will be somepony who will know what to do."

Spike looked up at her. "Thorax saw you being chased by all those unicorns back in the cave. He disguised himself as you to lead them away, and I tried to follow him, but…he got caught well before I could reach him. They tried to make him go after the second artifact, but I don't think they got far before they found out…"

"He…led them away from me?" Twilight asked, her eyes wide.

Twilight now realized that Thorax's actions were the reason she had managed to get away from that huge crowd of unicorns chasing her. There were many questions she wanted to ask, things she wanted to say to him, but she knew that now wasn't the time. Thorax could hardly focus on what they were saying at the moment, and they had to work on getting him help before they did anything else.

Walking closer, Spike climbed onto the couch and sat down next to Thorax. He had tried not to focus too much on the injuries that were visible along the changeling's right side and leg, but it had become impossible to ignore. In the light of the castle room, Spike could see much more clearly than he could in the cave. The burns and cuts along his side were obvious, but even those wounds didn't account for how weak Thorax was, and Spike knew that most of the damage was internal.

Twilight watched him sadly before turning to Sunburst. "Starlight was helping bring everypony from the hospital here. Can you try to find her, and bring her back here? We need somepony who can treat him, and Starlight would know where the ponies from the hospital were setting things up."

"Are you sure you'd be alright without me?" Sunburst asked, glancing from Twilight to Spike and finally to Thorax.

"Yeah, it'll be fine," Twilight responded. "And please let the doctors and nurses know about Thorax, so they can help as soon as they can."

"Okay," Sunburst replied, still looking concerned. "That is a good idea. I'll see if Starlight's here already."

As he opened the door to leave, Twilight caught a glimpse of frantic ponies racing through the hallway outside, many of them carrying or pushing carts of various supplies. Some of them were shouting with urgency. Twilight felt another pang of anxiety as she realized just how serious the situation had become, and how the whole empire – and everypony who'd decided to visit it – was in great danger. How could things have gone so wrong so quickly?

The door closed, but Twilight's worry didn't fade. Would the magic shield protect everypony long enough? What if the cave unicorn that had told Thorax about their "window of opportunity" was wrong or was somehow lying? What if their power really didn't have limits?

She snapped out of her thoughts when she heard Spike ask Thorax if they could get him anything, and she knew that she needed to focus on what was important at that moment. She could figure out the rest later.

"I…can I have some more water?" Thorax said, his voice still raspy.

"Yeah, I'll be right back," Twilight said before Spike could answer, picking up the empty glass in her magic. She walked out the door, trying to block out the noise from the other ponies. She quickly made her way to the kitchen and began filling the cup with water.

She then heard a distant booming sound, seeming like it was coming from the edge of the empire but loud enough to hear from where she was. She jumped, the glass of water dropping and shattering on the floor. She mumbled a quick apology to the ponies working in the kitchen as she lifted the pieces off the ground and reached for another cup.

She tried to remain calm and focus on her simple task, but in the back of her mind, she knew the danger that was fast approaching. Scarlet's unicorns had reached the edge of the magic barrier protecting the empire.


	10. Restless Night

**Beneath the Surface**

**Chapter 9 – Restless Night**

Twilight wasn't sure how long she and Spike waited in the small room with Thorax, while her friends, the castle guards, and other volunteers rounded up everypony currently in the empire. She knew that they probably hadn't been waiting long, but her growing anxiety and the distant sounds of spells clashing with the magical shield that surrounded the crystal city made it seem like an eternity. Would the protection spell hold out long enough? Would they be safe in the castle?_ Would…Thorax be okay?_

Thorax was still lying on the couch, barely moving, but he had become more alert and able to follow Twilight and Spike's conversations easier. Twilight had been quietly talking with Spike when the door to the room opened and Sunburst appeared.

He gave them a hopeful smile, but they could still see his unease. "Twilight?" he said urgently. "Starlight just came to talk to me, and she said that the ponies from the hospital are all here. They've set up a place in the dining room for anypony who's sick or injured. Starlight had to go help move some more supplies into the castle, but I told the doctors about Thorax and we can take him there now."

"The dining room, right," Twilight said, relieved that they could finally bring Thorax to ponies who would know what to do for him. She had recovered enough strength that teleporting was going to be easy, so she checked that Thorax was ready as she lit her horn.

"Starlight wanted me to help her," Sunburst explained. "If you need any help, though, you can send somepony to find us."

Twilight nodded and then teleported herself, Thorax and Spike to the dining room, taking care that the trip was as smooth as possible for the changeling.

The castle's dining room had been cleared of all its tables and chairs, and a sort of makeshift infirmary had been set up in their place. The room was large, wide, and would usually have plenty of space, but all the beds, equipment and ponies made it seemed cramped. A few guards were helping to carry beds into the room while the doctor and nurse ponies checked on the patients. The ones that did not seem to have any serious illness or injury were waiting on one side of the room. They seemed quite confused about the sudden decision to move everypony from the hospital, if their worried whispers to each other were anything to go by.

A group of waiting patients stopped talking when they noticed Twilight, taking in the princess's dirty and exhausted form with looks of horrified surprise. A couple of them noticed Thorax and stiffened. "What's…going on?" a crystal mare asked. "Everypony's been saying different things, and now Twilight-"

"I'm sorry, we can't explain right now," Twilight said, waving a hoof toward one of the nurse ponies, who quickly noticed her. The nurse called out to another crystal pony who was talking to a foal lying on one of the smaller beds. It suddenly occurred to Twilight that the Crystal Empire had reappeared after a thousand years, and they'd only had a relatively short amount of time to catch up with the rest of Equestria in medical technology. She told herself that it had still been a while; they had to have learned a lot from the ponies of modern Equestria, but what if…?

Her thoughts were interrupted as a light green crystal pony wearing a doctor's lab coat rushed over to them. Just then, Twilight noticed that Thorax was shaking, his eyes wide in fear.

Twilight then realized that he'd probably never been to a pony doctor before. And with what she knew of the changelings before Chrysalis was overthrown, she imagined that being treated for injuries in the hive had been anything but pleasant. "Don't worry," she told Thorax, trying to disguise any anxiety in her own voice. "They'll know what to do." To her dismay, Thorax didn't seem reassured, and just continued staring straight ahead and trembling.

The doctor glanced back at the nurses moving between the beds, and then back at Twilight and her two friends. "Sorry, there aren't any beds left, but ponies are working to bring in more from around the castle. We'll get one for him soon, but we need to take care of him now." She took a blanket offered to her by a nearby volunteer pony and spread it on the floor near the wall, out of the way of most of the bustling ponies in the room.

Thinking it was the safest option, Twilight lifted Thorax onto the blanket with her magic, but he still gave a small cry of pain when he was set down. Twilight quickly apologized as Spike walked over and sat down on the edge of the blanket close to Thorax.

The crystal pony doctor began looking the changeling over as he lay on his uninjured side. Spike and Twilight waited anxiously, trying to drown out the chaotic noise of the other ponies moving around them. The bleeding from the cracks in Thorax's chitin had slowed down, so the doctor wasn't overly concerned with that at the moment, being focused on the more serious burns. Thorax watched the crystal mare warily, unable to quell his anxiety.

"How did this happen?" the doctor asked him.

"I…was hit by a spell," Thorax said quietly.

"It was Scarlet who did it," Spike blurted out.

"Scarlet's the leader of the unicorns that attacked Canterlot last night," Twilight added, not sure if it was a detailed enough explanation, but knowing that a full one would take too long.

"Was the spell the only thing that caused these injuries?" the mare asked Thorax, not asking Twilight for more clarification.

"I…I think so," Thorax replied.

"I saw what happened," Spike said, looking away from Thorax's wounds and down at his own claws. "It was definitely the spell. He was fine right before. And other than it knocking him to the ground, I can't think of anything else that would have caused this."

The doctor nodded to him. "How long ago did this happen?" she asked Thorax.

"I don't know," he mumbled.

"It was…" Twilight trailed off, realizing that even she couldn't be certain of what events had happened at what time while in the cave. "It couldn't have been more than an hour or two, I don't think. Spike, how long were you two there after…"

"It seemed longer than that," Spike replied, but it was clear that he didn't know either.

"Okay," the doctor replied. She turned again to Thorax, who still looked terrified. "You may be my first changeling patient," she said reassuringly, "but I've treated griffins, yaks, and dragons as well as ponies. So don't worry. We'll take good care of you."

Thorax looked surprised by her words, and he relaxed a bit. "All right."

The mare then began to ask him a series of questions to assess his injuries. Twilight and Spike watched as she questioned Thorax on where the worst of the pain was, then asked him to move his leg, wings, and other parts of his body. She would ask Thorax how severe the pain was during each portion of the examination. As she watched, it concerned Twilight that Thorax wasn't able to move his right wing or foreleg very well or without pain.

Afterward, the doctor looked to the three of them. "On my initial assessment, the wings themselves look fine, but it looks like the internal wing muscles are damaged. There is a similar problem with the right foreleg muscles. It looks like the most damage occurred on the right side where the spell struck him. He obviously has internal injuries, and we need to do more tests to assess the severity and to see how best we can help."

"Can you give him something for the pain?" Spike asked.

"I was just going to talk about that," the crystal pony replied. "We've never treated a changeling before. And we're not sure how pony medicine would affect him."

Twilight looked at a loss for what to say, suddenly wondering if there had been some book back in her library that would have helped with such a thing, when Spike cried, "You have to do _something!_" Twilight opened her mouth to say something to the dragon, but it was clear he wasn't paying any attention to her.

The pony doctor, however, turned to Thorax reassuringly. "While we may not know how regular pony medicines work on changelings, we do have some that are known to work well not only on ponies, but on other species such as griffins and dragons. Those would be less risky, and more likely to work. We can start by giving you a low dose of pain medicine and antibiotics. We'll keep checking on you and watch for any signs of side effects."

Twilight looked to Thorax, suddenly wondering, "What do changelings do for things like this? Whether it's caused by a spell or not?"

"I don't know," Thorax replied wearily. "I'm not a healer."

'_Right,'_ Twilight thought to herself sadly, knowing that there was no way for the changelings or anypony working with them to safely send any supplies or changeling remedies to the Crystal Empire. Not with the blizzards and the small army of powerful magic users approaching.

The crystal pony doctor then interrupted to tell them she would be right back, and left to get the supplies she needed.

"They…the changeling healers…don't have the skills in healing that ponies seem to," Thorax rasped. "Or at least they didn't when I left. Not like all this." He moved his head a bit to look toward a place off to the side of the room where hospital equipment had recently been brought in. "Or at least I never saw anything like it. The healing chambers weren't nearly as clean and organized."

Twilight looked at him in disbelief; the dining room was currently the opposite of organized, but before she could reply, the doctor arrived with a case of supplies.

The crystal mare carefully poured a thick liquid from a bottle into a small cup and held it out to the changeling. "Drink this, it will help with the pain."

Thorax did so, and then he made a face, his forked tongue flicking out in disgust. "Sorry," the doctor told him, "I know it tastes bad. But it'll help."

She then began sorting through her supplies. "First, we need to clean you up, especially the wounds. Otherwise, they could easily get infected. I'll try to be as gentle as I can, but I have to warn you that it will still hurt."

The crystal pony pulled out a clean cloth from the case of supplies, poured some antiseptic solution on it and began using it to carefully clean the changeling's wounds. Thorax gritted his teeth, turning his head away when his eyes started to water.

Twilight was about to say something to him, but before she could, she was interrupted by a new commotion as a group of ponies suddenly entered the room, some of them with visible injuries. One of the nurses spotted Twilight and Spike and went over to them, quickly realizing that they had no wounds needing medical care.

"I'm sorry, but you two need to leave," she told them. "We have lots of ponies that need help, and there's hardly enough room as it is. We need all the space we can to take care of our patients."

"No, we need to stay here!" Spike protested.

"Sorry, but you need to leave now," the nurse told him. "You can come back as soon as things calm down."

"Spike, I think we have to," Twilight said reluctantly.

"It's…it's fine," Thorax said. "I'll be alright."

Twilight and Spike gave him a quick goodbye. Then they stood up and headed toward one of the doors, glancing behind them at Thorax before a group of ponies blocked their view.

As they made their way back into the castle hallways, trying to stay out of the way of any ponies rushing by, they noticed from a window up ahead that it was getting darker outside. Twilight knew that the sun would probably be setting now, but she also realized that most of the darkness came from the storm clouds moving over the empire.

Twilight then noticed that many of the crystal ponies – and other ponies who had been visiting for the faire – were all looking to her and Spike hopefully as they walked by. It was like they expected them to have answers, and Twilight found herself worrying that her failure to destroy the artifact had only made things worse. She avoided their gazes, and without really meaning to, her hoofsteps had soon led her to the room where she and Spike had been staying at the start of the Crystal Faire. Yesterday. It had only been yesterday.

Quietly, they both slipped inside. Twilight noticed that while all her belongings were still there, the bed had already been moved to the makeshift hospital. She didn't mind at all. She sat down on a rug in the center of the floor, thinking over everything that had happened. As Spike sat down beside her, Twilight looked to him to see that he had tears in his eyes. "Spike?" she asked. "Are you-"

"Everypony here is in danger now," he said, not taking his eyes off the floor. "And I don't think they know if Thorax is gonna be okay. It sounded like-"

"Thorax is in good hooves now," Twilight told him. "They'll do all they can, and we can go see him as soon as they let us."

"_Who_ would make a spell like that?" Spike said, slamming his fist against the floor. "I mean, what kind of horrible creature would you have to be to do…something like that?" Though he didn't say anything more, Twilight knew he was remembering the moment Scarlet had attacked Thorax.

Twilight opened her mouth to say something, but a knock on the door interrupted her. Wondering if it might be Cadance or her brother, she stood up and walked over to the door, opening it.

Rarity stood in the doorway. She was exhausted, her mane and coat disheveled, but her eyes looked to Twilight kindly. "Twilight, I was just coming up here to take your things to the throne room with the rest of our luggage."

"The throne room?" Twilight asked, Rarity's words registering far slower than they should have.

"Yes," Rarity said, nodding. "All of us – well, our group – will be staying there. Cadance thought it would be best. She and your brother – and Flurry of course – will be there too. Cadance wanted all the alicorns in one place, I believe so that they can be more easily protected. And, also, Cadance and Shining Armor wish to speak with us."

"Oh. Right," said Twilight, realizing that they each still needed to tell their story of what happened in the cave. She turned to look back into the room. "Spike?"

"I'll go," Spike said, slowly rising to his feet and heading out the door beside Rarity, who looked down at him in concern.

Rarity then went inside the room to retrieve Twilight's possessions, and a thought suddenly came through to Twilight. She turned to Spike. "Spike…Luna and Celestia didn't realize the unicorns from the cave were after_ any_ alicorn. We need to tell them."

As soon as Rarity returned, Twilight looked through her bags until she found a pencil and some paper, scribbling down a quick note for Celestia on what they had learned. She was sure it sounded disjointed and rushed, but at the moment, she couldn't care. She then handed it off to Spike, who blew a stream of green dragonfire on it and watched as the letter disappeared in a plume of smoke.

Rarity then led the two of them through the hallways, which had become a bit quieter in spite of some ponies still rushing back and forth. Twilight noticed that the air had become much colder, even in the short time she had been in her room. Perhaps she simply hadn't noticed before, but now the first effects of the north blizzards were impossible to ignore.

When they reached the throne room, Twilight almost didn't recognize it. The darkness brought on by the storm and the setting sun made the place look gloomy; ponies had only kept on some smaller lights. The entire floor was covered with makeshift sleeping areas made out of blankets and pillows. Twilight then noticed the area close to the throne itself where her friends had set up their own. Not far away, Shining Armor and Cadance were sitting with Flurry Heart in their own pile of blankets.

Twilight allowed Rarity to move her belongings over by those of her friends. She stepped around the blankets and the anxious ponies resting, making her way to Shining.

"Twily, I know you're exhausted," Shining Armor said sadly, giving her and Spike and apologetic look. "But we need to know what happened, and as much about those unicorns as you could find out."

"It's okay, I understand," Twilight said. She glanced at his and Cadance's sleeping area. "You're really staying here?" she asked.

"We wanted to stay where Flurry Heart could be more protected, and where we could best protect more of our subjects," Shining replied. "Most of the guards are elsewhere in the castle looking over other groups, but we wanted to be here to help you and Flurry if needed. And with your friends having the rest of the Elements of Harmony, they can also help us."

"But first, let's go to a quieter place so you can explain things," Cadance said. "Then we can come back here and rest."

As they walked over to Twilight's Ponyville friends, Twilight looked out a window and noticed that the shimmering magical barrier that had protected the empire was now much closer, encasing only the castle itself. She knew that the smaller barrier would be stronger, and it helped her relax a bit.

When the group was gathered together, Cadance left Flurry Heart with Sunburst. Then she led the group out of the throne room, a short way down a hallway, and into a fairly quiet room. Nopony else was in there, as it was mostly taken up by supplies brought in by the crystal ponies just an hour or so ago.

"I know you all have been through a lot," Cadance told the group. "But please, tell us what happened." Beside her, Shining gave them an encouraging smile.

None of them were keen to be the first to speak, but in the end, Twilight started. One by one, each of them recounted the events they had experienced underground. When it came to Spike's turn, he felt odd explaining what he'd seen happen, knowing that there was a big chunk missing that Thorax wasn't there to elaborate on. He tried to piece together what he'd overheard the cave ponies say in that room with the large crystal ball, but he couldn't be sure he had heard everything. He could only explain as much as he could remember.

When everypony had finished their explanations, they sat in silence for a few moments. For the first time each of them understood the whole picture, or at least as close to it as they could get in the current circumstances, of what had happened after they'd entered the cave and their group had been split up.

After a bit more silence had passed, Rainbow Dash stamped her hoof on the ground. "They think they _need_ an alicorn. Doesn't matter which one. And these guys are even willing to take Flurry Heart if nothing else works out good enough for them. As soon as their 'window of opportunity' is over and their magic or whatever runs out, I'll…"

Twilight felt another twinge of fear at Rainbow's words. Something that had been at the back of her mind ever since they were forced to flee was surfacing, and she felt tears coming to her eyes. "I…failed. I'm so sorry. I put the whole empire in danger, and even Flurry-"

"What?" Rarity gasped. "Twilight, nopony blames you."

"If we're blaming anypony, it should be Scarlet and whoever else follows her orders," Rainbow added.

As the rest of her friends joined in reassuring her, Twilight knew deep down that they were right, but still couldn't help feeling at least somewhat responsible. The cave unicorns had come to the Crystal Empire when they wouldn't have known about any alicorns there had she and her friends not…

"We…should have been more prepared," Twilight said. "Thorax paid the price for that. And Cadance and Flurry Heart and are danger…when they wouldn't have been if I had just been able to-"

"Come on, now," Applejack said, coming to stand next to her. "That ain't true. We all chose to go with you. An' Thorax chose to put himself in danger to help you. I mean, I sure felt bad when they made me give up the empire's secrets. But we all did the best we could. It ain't nopony's fault they had the advantage."

"I…I know," Twilight said. "But I thought I could do this. I should have tried harder to find out more. I shouldn't have-"

"Twilight, listen to me," Applejack continued. "Nopony's blamin' you. And you shouldn't blame yourself. Besides, you're the one who got most of us outta there."

Twilight sighed. "I was right there. Right where the cursed artifact was. I just wonder if things might have been different…if I'd just stayed a bit longer. Maybe tried more spells. I might have destroyed it."

"You were focused on getting us all out safely," Fluttershy said. "That was more important."

"And what's important now is to figure out how to move forward," Cadance added.

Twilight tried to push the sadness and guilt to the back of her mind, to focus on something more productive, at least. "You're right. I guess, in the meantime, we should try to figure out whatever we can about those unicorns. In case…" She trailed off, wondering how they would learn more while only being able to observe their enemies from inside the magic sphere surrounding the castle. Even if they could get to the Crystal Empire's library, there would be nothing there about a curse that happened only a few decades ago.

"We could…try talking to them," Starlight said. "Safely, I mean. Maybe there's a chance that-"

"Celestia tried, and look where that got her," Rainbow interrupted. "I don't think these guys can be reasoned with."

"Luna did say that they tried," Twilight added, her already low hopes fading.

"Of course we will try to talk to them," Shining Armor told the group. "But tonight, we first need to focus on keeping everypony as safe as possible. Cadance and I will be taking turns powering the protection spell around the castle."

"I gotta admit, I don't have much hope that they're gonna listen to us," Applejack sighed.

Several members of the group also began to express their doubts. Starlight watched them, at a loss for words. She didn't want to believe them, remembering how she was once a pony they likely also believed couldn't be reasoned with. However, though she didn't want to admit it, she had her own doubts about the situation. Suddenly she wanted to be anywhere but there.

"I…think I should go back to the throne room," Starlight said. "It's getting late, so I'll go make sure all our sleeping places are ready."

"Oh, all right," Twilight said, looking over to her. Starlight, however, had already left the room.

Pinkie Pie tilted her head at the still-open door. "I…thought we all set up our blankets and stuff already."

In the hallway, Starlight could still hear some ponies moving about in the dimly lit castle, but she hardly paid attention. Most of them were probably getting to sleep, and she hoped she would also be able to. When she made it back to the throne room, she could see that the windows were dark. At least Luna could still raise the moon.

As she made her way toward the sleeping area that she and her friends had set up, she noticed something else in the windows. Flurries of snow were blowing past, far too close to the window to be behind the magical shield. _'Right,'_ she thought. _'It keeps magic and enemies out, not the weather. That's the crystal heart's job._' The crystal heart that was now in the possession of their foe, she grimly remembered.

It certainly felt far colder than it had the previous night, when she and her friends had been sleeping soundly in their rooms, before Twilight had had the dream and woken them all up. She knew that the longer the crystal heart was away, the worse the storms would get. She suddenly wasn't sure if they were prepared enough.

She shook her head. She wasn't going to think about that now. Instead, she continued walking through the nearly-dark room toward where she and her friends had set up their belongings. As she got closer, she realized that they were already neatly lined up and there wasn't much for her to do. It had been a stupid excuse, but maybe she could at least make it look like she had improved something.

Then she noticed that another small sleeping area had been set up next to their group's. At first she didn't think anything of it, but then she realized that there wasn't a pony there; instead, Thorax rested on the blanket.

Forgetting about reorganizing her friends' sleeping areas, she walked over to his instead. He didn't look up as she approached, his eyes focused down on the blanket underneath him. She could see that his wounds had been treated and bandaged, but she wasn't sure what he was doing there. He was only lying on one blanket, a few others folded up to the side. Wasn't he cold?

When she had almost reached his blanket, Thorax jerked his head up in surprise. She could see the grimace in his face after he did so, and when he realized it was only her, he relaxed and lowered his head again to stare down at the blanket. The dim light from the crystals around the room caught on his wings, which still looked so shiny, beautiful and surprisingly undamaged. It was a sharp contrast to how defeated and hopeless he looked as he lay there in obvious pain.

"Thorax?" she asked, keeping her voice down so as not to attract the attention of any of the resting ponies around them. "What are you doing here?"

"I…wanted to stay with Spike and you guys," Thorax mumbled, his voice barely audible. "If that's okay."

"Well, sure it's okay, but shouldn't you be in the infirmary?" Starlight asked. "In a real bed? And they'd probably let you just stay in your room here in the castle if you wanted. It's got to be better than sleeping on the floor. I mean, there are a lot of ponies here and I'd think you would be more comfortable if-"

Thorax shook his head weakly. "I'd rather stay here. They can use the bed for somepony else. It's fine, I'm okay with it."

Starlight used her magic to pull her own blankets closer to his spot. Thorax made no movement as she did so. "Are…you okay?" she asked.

Thorax still didn't meet her gaze as he quietly said, "No."

Starlight immediately realized that was a stupid thing to ask. "You know, Twilight and I wouldn't have been able to get everypony out if it weren't for you. If they'd caught Twilight back there, it would've been over for us."

Thorax didn't reply, and Starlight wondered if he simply didn't believe her. "I'm not kidding," she said. "If Twilight hadn't gotten to that artifact and stopped it for a while, I don't think any of us would have gotten out of those caves. We all did what we could, and at least we're back in the empire and alive." Even though Thorax still did not respond, she continued. "Your shapeshifting abilities have helped others before. You took my place in Chrysalis's hive. Yeah, that ended better, but..." She trailed off, realizing that Thorax didn't even seem to be listening.

There was silence for a few moments as Starlight wondered whether she was actually helping or just making things worse. Thorax had said that he'd wanted to stay near her and her friends, but she wasn't sure he had much energy to talk to any of them, and she felt silly for not realizing that. She was about to apologize when Thorax broke down into sobs.

He was quiet enough that Starlight didn't think anypony else nearby had noticed. His face was buried in his good leg; obviously he was trying not to disturb the ponies around him.

Starlight's first alarmed thought was that she had just made things worse, somehow worse than they already were. But then she remembered that Thorax hadn't seemed to have been paying much attention to anything she was saying, and realized that wasn't it. He had just reached a breaking point after everything that had happened in the cave and the castle, all he had been through. Starlight herself was shaken up by what happened down in the caves, and she hadn't even seen the worst of it like he and some of the others had.

Thorax had suffered Scarlet's wrath directly; at least the rest of them had come out of the cave relatively unharmed. "I'm sorry," she said. "You've been through a lot."

Starlight got down on the floor in front of him, lifting up his chin with her hoof. "Thorax…look at me," she said, as Thorax's sobs started to fade.

Starlight wasn't sure how reassuring she could be, after all they'd been through, and knowing the danger was still there, but she wanted to try. "Look," she said, "I know that things aren't great right now…for any of us, really. You especially." She paused, but this time she could tell he was listening. "But…we're all in this together. I mean, they're going to have to get through some powerful spells and then the rest of us before they get to you, or Twilight, or…"

"They…they might break through, though," Thorax said, his voice shaking.

Starlight pushed back her own anxiety. "If they do, we'll deal with it. Me, Twilight, and the others. Plus every crystal pony willing to help."

"I…don't want any of them to get hurt," Thorax said quietly.

"No one does. But none of them are going to let anypony force one of the princesses to pour their life force into some long-buried artifact," Starlight replied. She sighed, glancing toward the windows and the snow billowing outside them. "I mean, they want to protect those they care about, just like you did."

Thorax pawed at the blanket with his good foreleg. "I'm…not sure I made a difference. I tried, but I didn't-"

"Are you kidding?" Starlight exclaimed. For the first time since they'd returned from the cave, she was smiling. "I saw you lead those unicorns away from Twilight. I mean, that's the main reason she was able to get to the artifact powering their spells and stop it for a while. The reason we could all escape. It was thanks to you, and Fluttershy, and Pinkie, and well, I think everypony there played a part. But if you hadn't sent them on a wild goose chase with your Twilight disguise, that would have been game over right then."

Thorax's eyes widened in surprise. "Really?"

"Trust me, we're lucky to have friends like you and the others," Starlight said. "You were all willing to put yourselves in danger to help the rest of us. You were all brave."

"I don't know," Thorax responded, wincing as he thought back to the events in the cave. "I didn't feel brave."

"But you did it anyway." Starlight smiled at him again, then looked thoughtful. "I told Cadance and Shining Armor we could try talking to the cave unicorns. I mean, this whole 'alicorn life force' thing can't be the _only_ way to fix their curse. I know that you always believed there was a better way for changelings to live, and you and I inspired most of the changelings to follow your example. Maybe this could be the same way…maybe there won't have to be any sort of fight."

"I…I hope you're right," Thorax replied, wiping a tear from his eye with his uninjured hoof.

Starlight nodded, then pulled him into a hug, careful to avoid touching any of his injuries. Thorax was surprised at the gesture at first, but quickly leaned into the hug. He closed his eyes, letting a few more tears escape. After a few moments, he relaxed.

Starlight let go, helping him to lay back down. "Don't worry. We'll all figure this out," she said. "Somehow."

"Thank you," said Thorax gratefully. "And thanks for rescuing me and Spike. He didn't want to leave me, and I was afraid…"

"Don't worry about it," Starlight said, using her magic to levitate one of the thick blankets over Thorax's back. She then began setting up her own blankets next to his. "We should get some rest. I'll be right here if you need anything."

Within minutes, they were both lying quietly under their blankets. They could hear the wind outside, and ponies moving in and out of the room, but they were too exhausted to pay much attention to it, or to whatever might be going on beyond the castle walls.

**-ooo-**

Twilight and her friends wearily returned to the throne room. They had spent more time than they'd anticipated talking with Cadance and Shining Armor, and they felt more exhausted than ever. Cadance had finally told Twilight and the others that, more than anything, they needed to rest for now, and they could think more about the situation tomorrow. As they stumbled into their sleeping areas, they noticed that Starlight had moved hers next to another.

"Thorax?" Spike asked quietly, realizing that the changeling was lying beneath a nest of blankets, only his head visible. He didn't react to Spike's voice, so he figured that Thorax was either asleep or close to it.

Starlight shifted among her own blankets, lifting her head to look tiredly at the group. "He wanted to stay here," she whispered, a yawn briefly interrupting her. "I think he felt safer with the rest of us. Let him rest right now, we can talk to him more tomorrow."

"How is he doing?" Spike asked anxiously.

"Well…" Starlight hesitated for a moment. "Better than before."

"Try not to worry too much," Twilight whispered to Spike as she led him over to the two blankets laid out at the edge of the group. "The ponies working in the infirmary must have thought he was okay enough to be moved here." She glanced back at Thorax, thinking again how much she wanted to thank him for that he'd done, but she knew she would have to wait until the morning.

"I…guess so," Spike said, lying down on his own blanket and pulling a few more over him.

As her friends all settled down to sleep, Twilight lay down on the blanket next to Spike's, shivering as she used her magic to pull a few more blankets over herself. She certainly felt tired enough to sleep, but her restless thoughts were keeping her awake. She tried to push the events of the day out of her head, but immediately knew that it would be a difficult task.

She lay there thinking, even after she was sure hours had passed. Sometimes she would fall into a light sleep, only to suddenly jerk awake with a feeling of danger to find nothing but the sleeping ponies around her. Eventually she decided to just keep lying still whether she was asleep or not, figuring that was better rest than nothing.

"Twilight?" came Spike's voice from the near-darkness.

Twilight turned her head toward him. "Yeah, Spike?"

"Celestia never sent a letter back," the dragon whispered.

Those words sent shivers through Twilight that had nothing to do with the cold. "Spike, I'm sure…Canterlot is still in trouble, so maybe she just..."

She trailed off, realizing that Spike had already started drifting off to sleep again. Wrapping her blankets tighter around her, she closed her eyes.

For the next several hours, Twilight tossed and turned, and it was near morning before she finally fell into a deeper sleep. After a while of slumber, Twilight found herself in another dream, this time in a version of the Crystal Castle filled with twisted dark crystals. Hearing strange voices, she fled down a hallway, only to realize that the hallway seemingly had no end.

Then at once, Luna was standing in front of her, and with a wave of her head, the dark crystals dissipated and faded. Twilight then became aware that she was dreaming. And all at once, her guilt at the failed mission came rushing back.

"Luna, I…I'm sorry. I tried what I could, but I didn't-"

"No," Luna said, her voice solemn. "You shouldn't be sorry. My sister and I…we didn't know that those unicorns would target any alicorn. They never said that was what they were after. Just Celestia. I don't think they even saw me before we put up the protection spell, which means they couldn't have known I'd returned. We should have been more careful. I am sorry, Twilight."

"Don't be sorry," Twilight said, wiping a tear from her eye. "We would have tried to help anyway. I just wish I could have…"

"You've done more than enough," Luna replied. "This is something that may require more discussion and planning. However, your letter to my sister gave us valuable information."

Twilight suddenly remembered Spike's words that she'd heard at some point during the night. "Has Celestia…had time to reply?"

Luna looked troubled. "You did not receive a reply?"

"…No," Twilight said, shivering. "They must have…those unicorns from the caves must have put some sort of magic-blocking spell around the place. Like the one they had in their caves. We could still use magic in the castle, but…"

"Nothing can get in or out?" Luna replied. "I was afraid they would do such a thing. However, it hasn't stopped me from reaching you in your dreams."

"Starlight wanted to try and talk to them," Twilight explained, "and I understand why, that maybe things can work out if we can at least understand each other, but…" She sighed. "I'm not sure they'll see reason, if Celestia couldn't convince them. But maybe…maybe if we could find another way to reverse their curse, we can stop this and fix everything."

"I hope so," Luna said. "Celestia and I cannot reverse a curse like the one befalling them with our own magic. I suppose for magic to be able to do anything, it would have to be a perfect world. These unicorns believe they need all of an alicorn's magic – and their life force – along with a second ancient artifact to undo their affliction. Celestia couldn't convince them otherwise. But maybe you can."

The vision of Luna and the endless crystal hall began to shimmer and fade around her, and Twilight knew that her time in the world of dreams was almost up. "I…I hope so," Twilight said.

"I believe in you," Luna said. "And I regret that you had to put yourself and your friends' lives in danger on our behalf." She smiled sadly, although it was hard for Twilight to see through the haze. "I am sorry."

That was the last Twilight heard before the vision faded and she returned to the waking world.


End file.
